WO2006085626A1

WO2006085626A1 - Exposure method and system, and method for fabricating device

Info

Publication number: WO2006085626A1
Application number: PCT/JP2006/302389
Authority: WO
Inventors: Kiyoshi Motegi
Original assignee: Nikon Corporation
Priority date: 2005-02-14
Filing date: 2006-02-10
Publication date: 2006-08-17
Also published as: JPWO2006085626A1

Abstract

An exposure system for enhancing line width uniformity of a pattern image being exposed onto an object such as a substrate. In the exposure system for exposing a wafer (121) with illumination light (IL) from a light source (101) through a reticle (119) and a projection optical system (120), a digital micromirror device (128) as a reflection element array including a plurality of mirror elements capable of respectively controlling the reflecting direction of the illumination light (IL) is arranged at a position substantially conjugate to the reticle (119) in an illumination optical system for illuminating the reticle (119) with the illumination light (IL), and illuminance distribution in the illumination region on the reticle (119) is controlled by controlling the reflection angle of each mirror element of the digital micromirror device (128) independently.

Description

Specification

Exposure method and apparatus, and device manufacturing method

Technical field

TECHNICAL FIELD [0001] The present invention relates to an exposure technique for exposing an object with an exposure beam. More specifically, for example, various devices such as a semiconductor element, a liquid crystal display element, an imaging element (CCD, etc.), and a thin film magnetic head are manufactured. The present invention relates to an exposure technique used to transfer a mask pattern onto a substrate during a photolithography process.

Background art

[0002] In a photolithographic process in the manufacturing process of a device such as a semiconductor element or a liquid crystal display element, a circuit pattern formed on a reticle (or photomask) as a mask is exposed to light as a substrate via a projection optical system. A projection exposure apparatus that projects onto a wafer or glass plate coated with a material (photoresist etc.) is used. As a powerful projection exposure apparatus, a step-and-repeat-type static exposure type (collective exposure type) exposure apparatus (for example, a so-called stepper) and a step-and-scan type scan exposure type exposure apparatus (for example, W Yuru Scanning (Stepa) etc. is used!

[0003] For example, as one basic function in a projection exposure apparatus used in a semiconductor element manufacturing process, the integrated exposure amount (integrated exposure energy) for each point in each shot area of a wafer is within an appropriate range. There is an exposure amount control function for storing. In a static exposure type exposure apparatus such as a stepper, the exposure dose control method is the basic regardless of whether a continuous light source such as an ultra-high pressure mercury lamp or a pulsed laser light source such as an excimer laser light source is used as the exposure light source. In particular, cut-off control was employed. In this cut-off control, a portion of the exposure light is split and guided to a photoelectric detector called an integrator sensor during exposure light irradiation to the wafer coated with the photosensitive material, and indirectly via this integrator sensor. The amount of exposure on the wafer is detected, and laser emission is continued until the integrated value of the detection result exceeds a predetermined level (critical level) corresponding to the integrated exposure amount required for the photosensitive material. Control is performed. Specifically, if the exposure light is continuous light, the exposure light path is changed to the shirt when the integrated exposure exceeds the critical level. When closed with a button, control is performed.

On the other hand, in a scanning exposure type exposure apparatus such as a scanning stepper, the above-described cut-off control cannot be applied because exposure amount control focusing on only one point on the wafer cannot be applied. Therefore, when the exposure light source is a pulse laser light source, the first control method is a method in which the amount of light from each pulse illumination light is simply integrated to control the exposure amount (open exposure amount control method). It was. As a second control method, for example, as disclosed in Japanese Patent Laid-Open No. 6-252022, a slit-shaped exposure region on a wafer (a region conjugate to a slit-shaped illumination region on a reticle). Then, the wafer is scanned relative to this exposure area.) The integrated exposure amount is measured in real time for each pulse illumination light, and the target energy of the next pulse illumination light is determined based on the integrated exposure amount. A control method (exposure control method for each pulse) is also used.

[0005] In addition, in the wafer process in the semiconductor device manufacturing process, the processes such as oxidation of the wafer surface (wafer surface), formation of an insulating film, electrode deposition, ion implantation, exposure, and etching are repeated many times. A circuit pattern is formed. In this process, when the wafer size increases from 6 inches (150 mm) to 8 inches (200 mm), and further to 12 inches (300 mm), the coating thickness of the photosensitive material is not uniform within the wafer surface. It may become. Further, even in the stage of developing the photosensitive material on the exposed wafer, a difference in development characteristics may occur depending on the location on the wafer surface. For these reasons, depending on the position of the shot area on a single wafer, and further, depending on the position within the shot area, there is a problem that the pattern line width shifts and the resolution deteriorates, resulting in a decrease in product yield. Yes. In order to solve this problem, in a scanning exposure type exposure apparatus, a method has been proposed in which the amount of pulse illumination light is adjusted according to the position on the wafer to correct the amount of light irradiated to the photosensitive material. (For example, see Patent Document 1).

[0006] In a scanning exposure type exposure apparatus, the integrated exposure amount at each point in each shot area on the wafer is an integrated value of illuminance in the scanning direction (short direction) of the slit-shaped illumination area. Therefore, in order to control the integrated exposure amount at each point on the wafer, an exposure apparatus has been proposed in which the width in the scanning direction of the illumination area is variable by a mechanical mechanism for each of a plurality of positions in the non-scanning direction. (For example, see Patent Document 2). Patent Document 1: Japanese Patent No. 3093528

Patent Document 2: JP-A-10-340854

Disclosure of the invention

Problems to be solved by the invention

[0007] In recent years, there has been an increasing demand for system LSIs in which a large number of functions are integrated on a single chip to have many functions. System LSIs have a structure in which single-function circuits are packed according to the application. With this structure, for example, a logic circuit and a memory circuit can be included in one chip, and a chip having both characteristics of logic and a memory such as DRAM, SRAM, and NVRAM (Non-Volatile RAM) can be manufactured. Such a semiconductor chip complicates the manufacturing process, and it is often necessary to optimize the process for each different circuit. For example, since the circuit dimensions sensitively affect the characteristics of each circuit, the optimal circuit dimensions differ between the logic portion and the memory portion on the same chip. In the future, as the degree of integration increases, the line width manufacturing accuracy (line width uniformity) of each circuit pattern will become stricter. On the other hand, as the number of circuits with different functions incorporated on the same chip increases, If it becomes difficult to transfer a pattern with the desired line width uniformity for each circuit having different functions, a problem will occur.

[0008] Further, due to the non-uniformity of the coating thickness and Z or development characteristics of the photosensitive material within the wafer surface, depending on the position of the shot area and also the position within the shot area of a single wafer. When the pattern line width shift or resolution failure occurs and the device yield is reduced, the amount of pulse illumination light depends on the position on the wafer as disclosed in the above-mentioned Patent Document 1 regarding the problem. However, there is a problem that the light amount distribution in the non-scanning direction cannot be corrected by the adjustment method.

[0009] Further, in order to control the exposure amount distribution in the non-scanning direction, a method disclosed in Patent Document 2 in which the width in the scanning direction of the illumination region is variable by a mechanical mechanism for each position in the non-scanning direction. However, because of the mechanical mechanism, it is difficult to change the width of the illumination area at high speed during stepping movement between shot areas or during exposure of one shot area.

The present invention has been made under such circumstances. A first object of the present invention is to provide an exposure technique capable of improving the line width uniformity of an image of a pattern exposed on an object such as a substrate. And

[0010] In addition, a second object of the present invention is to provide an exposure technique capable of improving the line width uniformity of an image of a pattern exposed on an object such as a substrate when performing scanning exposure. Suppose that

Another object of the present invention is to provide a device manufacturing technique using such an exposure technique.

Means for solving the problem

[0011] An exposure apparatus according to the present invention is an exposure apparatus that exposes an object with an exposure beam from a light source, and includes a plurality of reflective elements each capable of controlling the reflection direction of the exposure beam, and the exposure on the object. A reflection element array arranged between the light source and the object for adjusting the illuminance distribution in the illumination area of the beam, and a storage device storing exposure amount control data for controlling the exposure amount for the object; And a control device for controlling the reflective element array based on the exposure amount control data stored in the storage device.

[0012] According to the present invention, the illuminance distribution of the illumination area on the object can be controlled by independently controlling the reflection direction of the exposure beam by the individual reflecting elements of the reflecting element array. Therefore, since exposure can be performed with an optimum exposure amount for each of a plurality of local regions in the illumination region, the line width uniformity of the pattern image exposed on the object can be improved.

When the object is exposed through, for example, a predetermined pattern, the illuminance distribution in the illumination area of the exposure beam on the pattern is controlled. In the case of batch exposure, for example, when the integrated exposure amount for each local region on the object reaches an appropriate exposure amount, the reflective element that illuminates the local region is controlled, and thereafter, the local exposure is controlled. The area should not be illuminated by the exposure beam. This makes it possible to perform exposure with an optimum exposure amount for each local region on the object.

In the present invention, as an example, the reflective element array also has a digital micromirror device (DMD) force. Digital micromirror devices have hundreds of thousands to hundreds of minute reflective elements that can electrically control the tilt angle independently on a substrate such as silicon. About one million pieces are laid in a matrix. As the reflective element array, a digital micromirror device which is currently used for projectors, for example, can be used.

[0014] Further, as an example, each of the reflecting elements constituting the reflecting element array reflects the exposure beam in the first and second reflection directions so that the exposure beam from the light source is reflected. A beam splitter that leads to the reflective element array and a diaphragm member that shields the exposure beam reflected in the second reflection direction may be further provided. In this case, irradiation or non-irradiation of the exposure beam from each reflecting element can be switched by switching the reflecting direction of each reflecting element to the first or second reflecting direction. Therefore, the local illuminance distribution on the object can be controlled at high speed with a simple configuration.

[0015] Further, the exposure amount control data may be set so that the line width distribution of the pattern image formed on the object has a predetermined distribution. Thereby, the line width uniformity of the pattern image can be further improved.

Further, when the object is a substrate coated with a photoconductor, the exposure amount control data includes at least one of nonuniformity in the coating thickness of the photoconductor and nonuniformity in development characteristics depending on the position on the substrate. May be set so as to correct. As a result, it is possible to improve the deterioration of the line width uniformity due to uneven coating thickness or development characteristics of the photoreceptor.

[0016] Further, the reflective element array is disposed at a position that is substantially shared with the object between the light source and the object, or at a position that is offset by a predetermined amount of this conjugate power. Can do. When the reflective element array is placed at a substantially conjugate position, the illuminance distribution on the object is determined according to the distribution in the reflection direction of the exposure beam of the reflective element array, so the illuminance distribution can be easily controlled. . On the other hand, when the reflective element array is shifted by a predetermined amount of its substantially conjugate positional force, the image of the boundary of each reflective element in the reflective element array is not projected onto the object, reducing illuminance unevenness. It may be done.

[0017] In addition, the image processing apparatus further includes an arithmetic unit that calculates an integrated exposure amount of the exposure beam for the object during the exposure of the object, and the control unit includes an integration unit that is calculated by the arithmetic unit. The reflective element array may be controlled based on the exposure amount and the exposure amount control data. Thereby, the integrated exposure amount on the object can be controlled with high accuracy.

As an example, the exposure apparatus is a scanning exposure type that moves the object relative to the exposure beam during the exposure of the object.

[0018] Thus, when the exposure apparatus is of a scanning exposure type, the exposure apparatus further includes a position detection device that measures position information of the object in the scanning direction, and the control device is obtained by the position detection device. The reflective element array may be controlled based on the position information and the exposure amount control data. As a result, the line width uniformity of the pattern image exposed on the object after scanning exposure can be improved.

Further, the exposure amount control data may be set such that the integrated light amount in the scanning direction of the illumination area of the exposure beam is substantially uniform in the non-scanning direction orthogonal to the scanning direction. . In this case, the distribution of the integrated exposure amount on the object after scanning exposure becomes uniform. Of course, the exposure control data can also be set so that the distribution of the integrated light quantity in the non-scanning direction becomes non-uniform.

As an example, the reflective element array includes a plurality of reflective elements arranged in one or more lines in a region corresponding to a predetermined location in the scanning direction of the illumination region of the exposure beam. In this case, the one or a plurality of reflecting elements arranged in a line are arranged substantially in parallel in the non-scanning direction orthogonal to the scanning direction of the object, for example. As a result, the distribution of the integrated exposure amount after scanning exposure can be controlled only by using an elongated and small reflective element array.

[0019] Further, the control device may control the width of the exposure beam in the scanning direction in the scanning direction by controlling the reflective element array. As a result, the width of the illumination area can be controlled with high reproducibility at a high speed and with a fine pitch compared to, for example, mechanically controlling the width of the field stop of the illumination optical system. The distribution of integrated exposure can be controlled with high accuracy.

The exposure amount control data may be set for each of a plurality of partitioned areas on the object. Thereby, for example, even when the optimal exposure amount distribution differs for each of the plurality of partitioned regions on the object, the distribution of the exposure amount can be optimized for each partitioned region. [0020] Next, an exposure method according to the present invention is an exposure method for irradiating an object with an exposure beam from a light source to expose the object, and for each of a plurality of partitioned regions on the object. Is positioned between the light source and the object, and the reflection direction of the exposure beam can be controlled respectively. And a second step of controlling the illuminance distribution in the illumination area of the exposure beam on the object based on the exposure amount control data using a reflective element array including a plurality of reflective elements.

[0021] According to the present invention, the reflection direction of the exposure beam by the individual reflecting elements of the reflecting element array is controlled independently of each other, so that it is optimal for each of a plurality of local areas in the illumination area. The exposure can be performed with a proper illuminance distribution. Accordingly, it is possible to improve the line width uniformity of the pattern image exposed on the object.

The device manufacturing method according to the present invention uses the exposure apparatus or exposure method of the present invention. By applying the present invention, it is possible to improve the line width uniformity of a pattern image exposed on an object, so that a device having a configuration in which a plurality of circuits having different functions are combined like a system LSI can be manufactured with high accuracy.

The invention's effect

[0022] According to the present invention, exposure can be performed with an optimal exposure amount for each local region on the object.

Accordingly, it is possible to improve the line width uniformity of the pattern image exposed on the object such as the substrate. Brief Description of Drawings

FIG. 1 is a view showing a schematic configuration of a projection exposure apparatus according to a first embodiment of the present invention.

FIG. 2 is a view showing an exposure amount map on a reticle of the first embodiment.

3 is a view showing a reflection surface of DMD 128 in FIG. 1 corresponding to the exposure amount map in FIG.

4A is a diagram showing an example of an illuminance distribution in an exposure area on a wafer, and FIG. 4B is a diagram showing a corrected exposure dose map for correcting the illuminance distribution in FIG. 4A.

[FIG. 5] (a) is a diagram showing the exposure dose distribution to be corrected on the wafer due to the resist process, and (b) is a diagram showing a corrected exposure dose map on the reticle corresponding to FIG. 5 (a). .

[FIG. 6] (a) is a diagram showing an example of a change in integrated exposure amount of the first embodiment, and (b) is a diagram showing a change in energy per unit time corresponding to FIG. 6 (a). 7] FIG. 7 is a view showing a schematic configuration of a projection exposure apparatus according to a second embodiment of the present invention.

8 is a perspective view showing an optical path from the reflecting mirror 11 to the reticle R in FIG.

FIG. 9 is a perspective view showing a configuration of mirror element portions Dl and D2 of the reflecting mirror 11 of FIG.

FIG. 10 is a view showing an exposure amount map on a reticle R of a second embodiment.

FIG. 11 is a plan view showing a change in relative position between reticle R and illumination area 42R in FIG.

[FIG. 12] Each mirror element of mirror element portion D1 of reflecting mirror 11 in FIG. 7 at time t in FIG.

1

It is a perspective view which shows the state of ON or OFF of.

[FIG. 13] Each mirror element of mirror element section D1 of reflecting mirror 11 in FIG. 7 at time t in FIG.

2

It is a perspective view which shows the state of ON or OFF of.

[Fig. 14] Reflection mirror in Fig. 7 at time t in Fig. 11 when the appropriate exposure gradually increases.

2

FIG. 11 is a perspective view showing an ON or OFF state of each mirror element of the mirror element part D1 of the mirror 11.

[FIG. 15] (a) is a diagram showing the exposure dose distribution to be corrected on the wafer due to the resist process, and (b) is a diagram showing a corrected exposure dose map on the shot region corresponding to FIG. 15 (a). is there.

[FIG. 16] (a) is a diagram showing an example of the illuminance distribution of the exposure area on the wafer during scanning exposure, and (b) is the integrated exposure in the non-scanning direction after scanning exposure with the illuminance distribution of FIG. 16 (a). It is a figure which shows quantity distribution.

[Fig. 17] (a) is a diagram showing an example of the illuminance distribution when the width of the exposure area on the wafer during scanning exposure is controlled, and (b) is a diagram after scanning exposure with the illuminance distribution of Fig. 17 (a). It is a figure which shows the integrated exposure amount distribution of a non-scanning direction.

18] FIG. 18 is a diagram showing a schematic configuration of a projection exposure apparatus according to a modification of the second embodiment.

FIG. 19 is a perspective view showing an optical path from reflection mirror 11 to reticle R in FIG.

20 (a) is a diagram showing the illuminance distribution in the scanning direction of the illumination area 42R when all the mirror element portions D3 are turned on in the projection exposure apparatus of FIG. 18, and FIG. 20 (b) is the projection exposure of FIG. FIG. 6 is a diagram showing an illumination distribution in the scanning direction of an illumination region 42R when all the mirror element portions D3 are turned off in the apparatus.

Explanation of symbols [0024] 11 ··· Reflection mirror, Dl, D2, D3 "'mirror element, 12 ··· Illumination system, 13 ··· Beam splitter, 16 · ··· Excimer laser light source, · 33 · DMD drive device, · 37 · Condenser lens, PL: Projection optical system, R: Reticle, W: Ueno, SA ... Shot area, 42R ... Illumination area, 42 W ... Exposure area, 50 ... Main controller, 51 ... Storage device, 54W ... Laser interference Total 55 ··· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ··· Reticle, 120 ··· Projection optical system, 121… Ueno, ·························································

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment]

A preferred first embodiment of the present invention will be described below with reference to FIGS. In this example, the present invention is applied to the case where exposure is performed by a projection exposure apparatus comprising a strobe as a batch exposure type exposure apparatus.

FIG. 1 shows a schematic configuration of the projection exposure apparatus of this example. In FIG. 1, a mercury lamp 101 is used as a light source for exposure. However, exposure light sources include excimer lasers such as KrF (wavelength 248 nm) or ArF (wavelength 193 nm), and F lasers (wavelength 157 η).

2

m), a harmonic generator of a YAG laser, or a harmonic generator of a solid-state laser (semiconductor laser, etc.) can also be used. Illumination light IL as an exposure beam from the mercury lamp 101 is collected by an elliptic mirror 102, and then includes a condensing optical system 103a and an optical filter 103b for selecting light in a desired wavelength band (for example, i-line). It reaches the shirt 104 through the optical filter system 103. The shatter 104 is opened and closed by the shatter control mechanism 105 based on a command from the timer control system 106. When the shirter 104 is in the open state, the illumination light IL becomes a substantially parallel light beam through the input lens 107 and enters the fly-eye lens 108 as an optical integrator (unifomizer or homogenizer).

A large number of secondary light source images are formed on the exit surface of the fly-eye lens 108 (the pupil plane of the illumination optical system), and the illuminance distribution of the illumination light IL that illuminates the reticle 119 is thereby flattened. The illumination light IL that has passed through the fly-eye lens 108 enters the beam splitter 109 having a reflectivity of about 98%. Illumination light IL reflected by the beam splitter 109 is reflected by the first relay lens 113. After that, the illumination blind (variable field stop) 114 whose aperture shape is controlled by the blind drive system 115 is limited to a light beam that illuminates a predetermined variable illumination area. A main control system 125 that controls the operation of the entire apparatus controls the shape of the opening of the illumination blind 114 and the shape of the illumination area on the reticle 119 via the blind drive system 115. Illumination light passing through illumination blind 114 IL force Reflection of digital micromirror device (hereinafter referred to as DMD) 128 as a reflective element array via second relay lens 116, beam splitter 126, and condenser lens 127 Illuminate the surface with a uniform illumination distribution. As will be described later, the DMD128 includes a number of mirror elements as minute reflective elements with variable tilt angles of the reflective surface. The reflective surface of the DMD128 includes the pattern surface (pattern forming surface) of the reticle 119 as a mask. It is in a conjugate position. The main control system 125 independently controls the tilt angles of the reflecting surfaces of the individual mirror elements of the DMD 128 via the DMD driving device 131 (control device).

[0027] The reflected light from the DMD 128 passes through the condenser lens 127 and the beam splitter 126 again and is incident on the light shield 129 having a circular opening 129a formed at the center as a diaphragm member. Instead of the light shield 129, an absorber that absorbs light may be used. Many mirror element forces of DMD128 Illumination light IL reflected in a predetermined direction passes through aperture 1 29a of light shield 129 and then passes through condenser lens 118 to pattern in the illumination area of the pattern surface of reticle 119. Illuminate.

[0028] At least a part of a light source device for exposure is configured including a mercury lamp 101, an elliptical mirror 102, and a condensing filter system 103, and includes a shirter 104, an input lens 107, a fly-eye lens 108, a beam splitter 109, At least one of the illumination optical system including the first relay lens 113, the illumination blind (variable field stop) 114, the second relay lens 116, the beam splitter 126, the condenser lens 127, the DMD1 28, the light shield 129, and the condenser lens 118. The part is composed.

[0029] Under illumination light IL, the pattern in the illumination area of reticle 119 is projected on both sides (or one side) through telecentric projection optical system 120 (for example, 1Z4, 1Z5, etc.) Thus, projection exposure is performed on an exposure region on one shot region of the wafer 121 coated with a photoresist (photosensitive material or photosensitive material) as a substrate. The surface of wafer 121 is Each is divided into a number of rectangular shot areas (partition areas) onto which the pattern image of the reticle 119 is transferred. The illumination area on reticle 119 and the exposure area on wafer 121 are shared, and the exposure area on wafer 121 can also be regarded as the illumination area. The wafer 121 is a disk-shaped substrate having a diameter of about 200 to 300 mm, such as a semiconductor (silicon etc.) or SOI (silicon on insulator).

[0030] In this example, since the reflecting surface of DMD128 and the pattern surface of reticle 119 are arranged at optically conjugate positions, the distribution of reflected light of illumination light IL by each mirror element constituting DMD128 is as follows. This corresponds almost directly to the illumination distribution of the illumination area of the reticle 119 (or the exposure area on the wafer 121). However, if the boundary of each mirror element on the DMD128 is projected in a grid pattern on the no-turn surface of the reticle 119 and the illuminance distribution is likely to deviate from the allowable range, the reflective surface of the DMD128 is moved over the reticle 119. Place yourself at a position that deviates from the position conjugate with the pattern surface by a predetermined amount (in this case, until the illuminance distribution falls within the allowable range).

In the illumination optical system, the illumination light transmitted through the beam splitter 109 is incident on an integrator sensor 111, which is a photoelectric conversion optical sensor, via a condenser lens 110, and this output signal is an illuminance calculation system 112. To be supplied. For example, the integrator sensor 111 is at a position substantially conjugate with the pattern surface of the reticle 119. For example, in the case where a circuit pattern is formed on the reticle 119 (transmittance is 1), the conversion coefficient between the exposure energy per unit time on the wafer 121 and the illuminance on the integrator sensor 111 is calculated in advance. It is stored in the illuminance calculation system 112. In the illuminance calculation system 112, the exposure energy (illuminance) per unit time on the wafer 121 is obtained by multiplying the output signal of the integrator sensor 111 by the conversion factor. The obtained exposure energy per unit time is supplied to the main control system 125 (arithmetic unit for obtaining the integrated exposure amount). Further, the exposure time obtained by dividing the appropriate exposure amount on the wafer 121 (photoresist) by the exposure energy per unit time at the time of exposure is input to the timer control system 106. In response to this, the timer control system 106 can control the exposure amount on the wafer 121 by opening the shirter 104 for the exposure time as an example.

[0032] However, in this example, as described later, also in DMD128, the reflection angle of each mirror element is controlled. The exposure time (integrated exposure) for each illumination light reflected by each mirror element can be controlled.

There are also multiple partial areas (local areas) PTi (i = l, 2, ...) with different pattern characteristics (pattern line width, pattern repetition period (pitch), pattern density, etc.) on reticle 119 In this case, the integrated exposure amount is controlled for each of the plurality of partial areas PTi on the reticle 119. Therefore, for each partial area PTi on the reticle 119, an appropriate exposure amount Pi determined according to the characteristics of each partial area PTi is obtained. Then, by dividing the appropriate exposure dose Pi for each partial area PTi by the exposure energy E per unit time on the wafer 121, the exposure time ti (i = l, 2, 3, ...) for each partial area PTi Is required.

[0033] That is, there is the following relationship.

ti = Pi / E (i = l, 2, ...)

The exposure energy E per unit time on the wafer 121 can be determined by measuring the average exposure energy reaching the image plane side of the projection optical system PL before starting the exposure of the wafer 121. Further, in this example, the exposure time ti is supplied to the longest time ti force timer control system 106, and the shirter 104 is closed when the maximum exposure time ti has elapsed max max.

[0034] Further, in this example, when the integrated value of the exposure energy ΔE per unit time measured via the integrator sensor 111 becomes the appropriate exposure amount Pi, the partial area P Ti is exposed. Stop. That is, the main control system 125 controls the tilt angle of each mirror element of the DMD 128 based on the integrated value of the exposure energy ΔΕ per unit time measured via the integrator sensor 111, and thereby controls each partial region PTi. The exposure time is controlled for each partial area PTi so that the integrated exposure amount becomes the appropriate exposure amount Pi. Thereby, the integrated exposure amount is optimized according to the pattern characteristics on the reticle 119, and the line width uniformity of the pattern image in the shot area can be improved.

[0035] When a shot area on wafer 121 is exposed through reticle 119 having a plurality of partial areas PTi having different pattern characteristics as described above, partial areas on reticle 119 are exposed during the exposure of the shot areas. By controlling (adjusting) the illuminance distribution in the illumination area corresponding to PTi, the integrated exposure amount for each local area in the shot area corresponding to that partial area PTi Can be optimized.

Note that the appropriate exposure amount Pi for each partial region PTi on the reticle 119 is stored in advance in the storage device 130 connected to the main control system 125 as exposure amount map information. For example, the exposure map information is created based on the measurement result obtained by transferring the pattern on reticle 119 onto a test wafer, measuring the test wafer, the line width of the pattern image formed on the test wafer, and the like. This is data obtained so that each pattern has a desired line width in the shot area (first step).

[0037] Further, in the storage device 130, as will be described later, the image generated due to unevenness in the illumination light IL by the illumination optical system, unevenness in the coating thickness of the photoresist on the wafer 121, and unevenness in development. A correction map is also stored that includes a corrected exposure that is added to the integrated exposure (or subtracted if the value is negative) to correct changes in the line width of subsequent patterns. As an example, the correction map may be set for each partial area obtained by further dividing each force shot area that is set for each shot area on the wafer 121. At the time of exposure, the main control system 125 adjusts the illumination light IL in order to obtain a desired distribution of the integrated exposure amount of each shot area on the wafer 121 based on the exposure amount map and the correction map stored in the storage device 130. Control irradiation. As an example, during the exposure of each shot area, each partial area is subjected to exposure so that the distribution of accumulated exposure obtained by adding the exposure determined by the correction map to the appropriate exposure determined by the exposure map described above. The illuminance distribution of the illumination light IL is controlled (second step). In this case, the control of the illuminance distribution includes at least one of the control of the illuminance distribution in the illumination area on the reticle 119 and the control of the illuminance distribution in the shot area on the wafer 121.

[0038] Hereinafter, the Z-axis is taken in parallel to the optical axis AX of the projection optical system 120, the X-axis is taken in a direction perpendicular to the paper surface of FIG. 1 in a plane perpendicular to the Z-axis, and parallel to the paper surface of FIG. Take the Y axis in the direction. At this time, reticle 119 is held by suction on reticle stage 132, and reticle stage 132 positions reticle 119 in the XY plane on a reticle base (not shown). A laser interferometer system (not shown) for measuring the position of reticle stage 132 in the XY plane is also provided.

On the other hand, Ueno 121 is sucked onto wafer stage 133 via a wafer holder (not shown). The wafer stage 133 is stepped in the X and Y directions within the XY plane on the wafer base 134 to position the wafer 121. A laser interferometer system (not shown) for measuring the position of the wafer stage 133 in the XY plane is also provided. The main control system 125 performs positioning of the reticle stage 132 and step movement of the wafer stage 133 based on the measurement values of these laser interferometer systems. Further, a reticle alignment microscope (not shown) for aligning the reticle 119 and an alignment sensor (not shown) for aligning the wafer 121 are also provided.

[0040] At the time of exposure of wafer 121, illumination light IL is irradiated onto reticle 119, and the pattern of reticle 119 is transferred onto one shot area on wafer 121 via projection optical system 120, and the wafer. The operation of moving the next shot area on the wafer 121 to the exposure area of the projection optical system 120 by driving the stage 133 and moving the wafer 121 stepwise in the X and Y directions is repeated.

[0041] Now, when each shot area on the wafer 121 is exposed with an image of the pattern in the illumination area of the reticle 119, even if the pattern characteristics are different in a plurality of partial areas in the illumination area, this example is used. For example, by controlling the exposure time of the illumination light IL for the plurality of partial areas, the integrated exposure amount in each shot area can be set to a desired distribution. First, the configuration of DMD128 (digital microphone aperture mirror device) as a reflective element array used in the exposure amount control will be described.

[0042] As an example, the DMD 128 has hundreds of thousands of minute mirror elements (reflective elements) that can electrically control the tilt angle of the reflecting surface independently of each other at predetermined pitches in the X and Y directions on the lower surface of the silicon substrate. ~ It is made up of several million pieces. In this case, the illumination area on the reticle 119 is divided into a number of minute parts in the X and Y directions, and the mirror elements are irradiated so that illumination light from the corresponding mirror elements of the DMD128 is irradiated to each minute part. Are arranged in a matrix.

[0043] As the DMD 128, a digital micromirror device (DMD) that is currently widely used in projectors and the like can be used. When DMD is used in a projector, each mirror element changes its tilt angle by about ± 12 °. As an example, the tilt angles of + 12 ° and 12 ° correspond to the on and off states, respectively. Each mirror element can be switched on and off at a cycle of thousands of cycles per second by digital control. When each mirror element is irradiated with light of sufficient light source power, for example, the light reflected by the mirror element at 12 ° (off state) is absorbed by the light absorbing plate arranged separately, and + 12 ° (on state). The light reflected by the mirror element is applied to the screen through the projection lens. Then, the density of the projected image can be expressed by controlling the number of on / off times of a large number of mirror elements on the DMD.

[0044] In this example, the DMD is used to irradiate a reticle 119 instead of the screen. Currently available DMDs have 720 x 1280 mirror elements, so if the shot area on the wafer (shot size) is 20 x 35 mm ² , each mirror The illumination light from the element is equivalent to irradiating a 28 m square area. In addition, as shown in FIG. 1, the DMD 128 used in this example has an overall reflecting surface that is substantially perpendicular to the optical axis AX of the projection optical system 120. Therefore, each reflecting surface of each mirror element is It is desirable to tilt at 0 ° parallel to the plane perpendicular to the optical axis AX in the on state and to 12 ° or 112 ° relative to the plane perpendicular to the optical axis AX in the off state. At this time, in FIG. 1, the illumination light IL reflected by the on-state mirror element in the DMD 128 is reflected in the first direction, passes through the opening 129a of the light shield 129, and corresponds to the illumination area of the reticle 119. Illuminate the part. On the other hand, the illumination light IL reflected by the off-state mirror element in the DMD 128 is reflected in the second direction, is shielded by the light shield 129, and is not irradiated to the reticle 119. When a switching command is supplied from the main control system 125 to the DMD driving device 131, the DMD driving device 131 switches each mirror element in the DMD 128 on and off.

Next, the exposure amount control operation of this example will be specifically described. As shown in the exposure map in Fig. 2, the pattern area PA of reticle 119 is formed with several different types of circuits (three types in Fig. 2) and different pattern characteristics divided into partial areas PT1, PT2, and PT3. It is assumed that the appropriate exposure amount for each partial area is set to Dosel, Dose2, and Dose3. The appropriate exposure amount corresponds to the appropriate exposure amount Pi of each partial region PTi described above. Then, the exposure time for the partial areas PT1 to PT3 for obtaining the appropriate exposure amount is obtained by dividing the appropriate exposure amount Dose 1 to Dose 3 by the exposure energy 単位 per unit time, respectively. Here, the size of the appropriate exposure is Assume that you are in charge.

[0046] DoseK Dose2 <Dose3 · '· (2)

At this time, the largest dose 3 is used as the appropriate exposure amount for determining the upper limit of the exposure time when the wafer 121 is exposed via the reticle 119 of FIG. That is, the exposure time t3 corresponding to Dose3 is supplied in advance from the main control system 125 to the timer control system 106, and the shirter 104 is closed when the elapsed time corresponding to the exposure start force of each shot area reaches t3.

FIG. 3 shows partial regions MD1, MD2, and MD3 on DMD 128 corresponding to partial regions PT1 to PT3 of reticle 119 in FIG. Note that the arrangement shown in FIG. 3 is reversed with respect to the arrangement shown in FIG. 2 by the imaging optical system including the condenser lenses 127 and 118 shown in FIG. In the explanation of this example, for the sake of simplicity, the power to be divided into three partial areas is not limited to this. In principle, illumination is performed with the number of mirror elements constituting the DMD 128 as the upper limit. It is possible to divide the region.

Next, the operation of DMD 128 in FIG. 1 will be described. Prior to exposure, all mirror elements of DMD128 are in the ON state (no tilt), and the reflected light is ready to illuminate all pattern areas of reticle 119 (assuming they match the illumination area). ing. Since an area on the wafer 121 that is not desired to be exposed generally corresponds to a light shielding pattern on the reticle 119, it is not necessary to consider an area having an appropriate exposure amount of zero. However, if correction exposure is performed on a shot area on a wafer once exposed, there may be an area where the appropriate exposure is set to zero. In such a case, the mirror element corresponding to the region can be initially turned off (with tilt). Also, if you want to expose some areas in the shot area under different exposure conditions (polarization characteristics of exposure light, illumination, etc.) than other areas, the mirror element corresponding to that area After performing exposure in the off state (with tilt) from the beginning, the exposure conditions may be changed to perform exposure with only the mirror elements corresponding to a part of the region turned on (no tilt).

[0049] When the shatter 104 is opened and exposure is started, the main control system 125 accumulates the value of the exposure energy ΔΕ sent to the main control system 125 by the illuminance calculation system 112, and the reticle 119 is The integrated exposure dose irradiated to the wafer 121 via . First, when the integrated exposure amount reaches the smallest optimum exposure amount Dosel, all mirror elements in the corresponding partial area MD1 of the DMD 128 in FIG. 3 are turned off. At this time, since the mirror surface is inclined, the reflected light having the mirror element power in the off state is not guided to the condenser lens 118 in FIG. For this reason, the partial area PT1 of the pattern area PA of the reticle 119 in FIG. 2 is not illuminated, and the local area in the shot area on the wafer 121 corresponding to this area is not irradiated with the illumination light IL thereafter. That is, the partial area PT1 is controlled to the appropriate exposure amount Dosel. Subsequently, when the integrated exposure amount reaches the appropriate exposure amount Dose2, all mirror elements in the partial region MD2 of the DMD 128 are turned off, and the local region in the shot region on the wafer 121 corresponding to the partial region PT2 of the reticle 119 The area is not irradiated with illumination light IL thereafter. That is, the partial area PT2 is controlled to an appropriate exposure amount Dose2. Further, when the integrated exposure amount reaches the appropriate exposure amount Dose3, the shirter 104 is closed, so that the local region in the shot region on the wafer 121 corresponding to the partial region PT3 of the reticle 119 is subsequently irradiated with the illumination light IL. The partial area PT3 is controlled to an appropriate exposure dose Dose3. As a result, the entire shot area on the wafer 121 is exposed with an appropriate exposure amount. At this time, all mirror elements in the partial region MD3 of the DMD 128 are turned off based on the integrated value of the exposure energy Δ Δ per unit time, and the shot region on the wafer 121 corresponding to the partial region PT3 of the reticle 119 Even if the illumination light IL is not irradiated to the local area, there is no problem.

Thus, according to the present embodiment, for example, when exposing a pattern of reticle 119 having locally different pattern characteristics on wafer 121 as in a system LSI, for each local region. The exposure time of the illumination light IL is controlled for each local region using the DMD 128 so that the exposure is performed with the optimum integrated exposure amount. Therefore, the pattern image can be transferred with the optimum integrated exposure amount over the entire shot area on the wafer 121, and the line width uniformity of the pattern image is improved.

[0051] Note that, in order to correct the illuminance uniformity of the illumination light IL by the illumination optical system, which is obtained by using only the components set in accordance with the pattern characteristics as described above, as the optimal setting value of the optimum exposure amount. Or a component (correction map) resulting from the resist process may be superimposed. That is, the illumination light IL has a uniform illuminance over the entire exposure area on the wafer. However, there is a case where the illuminance distribution is not always uniform.

For example, FIG. 4 (a) shows an example of the illuminance distribution of the exposure region 135 on the wafer. In FIG. 4 (a), the peripheral region of the exposure region 135 has lower illuminance than the others. And In order to correct this, as shown in FIG. 4 (b), a correction map is set in the illumination area 135M of the reticle to set a larger exposure amount in the peripheral area than in other areas. In other words, the correction map in Fig. 4 (b) shows the illuminance (exposure per unit time) that makes the illuminance uniform over the entire exposure area 135 when added to the illuminance distribution in Fig. 4 (a). This is a map of correction values. Corresponding to the correction value, the exposure time to each partial area by each mirror element of DMD128 in Fig. 1 is adjusted to obtain a more appropriate integrated exposure dose distribution for each partial area in the exposure area 135 on the wafer. Exposure can be performed.

On the other hand, the correction components resulting from the resist process are generally distributed concentrically with the central force of the wafer 121 as shown in FIG. In Fig. 5 (a), darker areas indicate that more exposure is required. For example, the correction map on the reticle focusing on the shot area F in the wafer 121 is shown in Fig. 5 (b), and the correction map shown in Fig. 5 (b) is set for each shot area in the wafer 121. Is done. If the reticle pattern shown in Fig. 2 is exposed, the exposure amount obtained by adding the exposure amount map shown in Fig. 2 to the exposure amount map determined by the correction maps shown in Figs. 4 (b) and 5 (b). Based on the map, the DMD 128 may be controlled to perform exposure as in the above embodiment.

Needless to say, the correction map can be determined similarly when the exposure dose component to be corrected due to the resist process is distributed elliptically with respect to the center of the wafer 121.

As described above, the force that forms a map of the optimum exposure amount for each shot area and performs exposure. The setting of the optimum exposure amount is about 70% if the maximum exposure amount is 100%: LOO Expected to be in the% range. In such a case, exposure may be performed in the shortest time, and the amount of light applied to the DMD 128 may be adjusted within one shot exposure time in order to perform exposure with high accuracy at each optimum exposure amount. That is, as shown in Fig. 6 (a), until the integrated exposure dose Σ Ε on the wafer reaches the minimum value Dosel (70% of the maximum value in Fig. 6 (a)) of Fig. 6 (b) Illuminance (unit area, energy per unit time) IU as shown in Increase to 70% in a short time. The horizontal axes in Figs. 6 (a) and (b) are the time ts from the start of exposure. For this purpose, the power to increase the output of the mercury lamp 101 in FIG. 1 or the amount of light reduced by the light quantity adjustment mechanism (not shown) disposed between the mercury lamp 101 and the fly-eye lens 108, for example, is reduced. do it. When the optimum exposure in Fig. 6 (a) is between 70% and LOO% of the maximum value, the illuminance IU is reduced as shown in Fig. 6 (b), and each mirror element is turned on. What is necessary is just to be able to control the switching time of OFF accurately.

In this example, the main control system 125 uses the DMD driving device 131 to provide each mirror element based on the integrated value of the exposure energy ΔΕ per unit time supplied from the illuminance calculation system 112. The on-state force of the control unit controls the switching timing to the off-state, but without using the output from the illuminance calculation system 112, based on the above equation (1), the partial areas on the reticle 119 PTl, PT2 The exposure times tl, t2, t3 for each local area in the shot area corresponding to PT3 and PT3 are obtained, and when the elapsed time of the exposure start force reaches the exposure times tl, t2, t3 in sequence, the partial areas The mirror elements in MD1, MD2, and MD3 may be sequentially switched to the on state force and the off state.

[0056] When the light source is a pulse light source such as an excimer laser, the energy per unit time described above (for example, the illuminance IU in Fig. 6 (b)) can be read as energy per pulse. Similar effects can be obtained.

When the energy of each pulse emitted is almost constant, the target irradiation pulse number Nl for each local region in the shot region corresponding to the partial regions PTl, PT2, and PT3 of the reticle 119 in FIG. , N2 and N3 are determined, and when the count value of the number of irradiation pulses from the start of exposure reaches the target number of irradiation pulses Nl, N2 and N3 in sequence, the values in the partial areas MD1, MD2 and MD3 in Fig. 3 The mirror elements may be sequentially switched from the on state to the off state.

Further, in this example, as described above, the force described as switching on / off of each mirror element of DMD128 during one-shot exposure As described above, each mirror element is alternately turned on / off during one-shot exposure. It is also possible to perform so-called duty control, which is repeated at high speed and adjusts the number of times of ON. The exposure amount control of this example is also effective in an exposure apparatus that uses an X-ray source as a light source. In this example, the illumination blind 114 is used to define the shape and size of the illumination area on the reticle 119. However, the size of the illumination area on the reticle 119 is also determined using the DMD 128. You may prescribe.

In addition, in this example, the force used to create a correction map to correct variations in pattern line width caused by uneven illumination intensity of illumination light IL, uneven application of resist, uneven development, etc. When the number is small, it is not necessary to create a correction map. Instead of creating a correction map, you may create only an exposure map that takes into account pattern characteristics, illumination illumination IL illumination unevenness, resist coating unevenness, and image unevenness.

[Second Embodiment]

Next, a second embodiment of the present invention will be described with reference to FIGS. In this example, the present invention is applied to the case where exposure is performed by a scanning exposure type projection exposure apparatus (scanning type exposure apparatus) comprising a scanning stepper.

FIG. 7 shows a schematic configuration of the scanning exposure apparatus 10 of the present example. In FIG. 7, this scanning exposure apparatus 10 uses a step-and-excitation using an excimer laser light source 16 as a Norse light source as an exposure light source. 'It is a scanning projection exposure apparatus. The scanning exposure apparatus 10 includes an illumination system 12 including an excimer laser light source 16, a reticle stage RST that holds a reticle R illuminated by illumination light IL from the illumination system 12, and illumination light IL emitted from the reticle R as a wafer. It includes a projection optical system PL that projects onto W, an XY stage 14 on which a Z tilt stage 58 that holds the wafer W is mounted, and a control system for these.

[0059] The illumination system 12 includes an excimer laser light source 16, a beam shaping optical system 18, an energy coarse adjuster 20, a fly-eye lens 22, an illumination system aperture stop plate 24, a beam splitter 26, a first relay lens 28, A reticle blind 30, a second relay lens 29, a beam splitter 13, a condenser lens 37, a reflection mirror 11 provided with a digital micromirror device, a light shield 55 as a diaphragm member, and a condenser lens 32 are provided.

[0060] Each component of the illumination system 12 will be described. As the excimer laser light source 16, a KrF excimer laser light source (oscillation wavelength 248 nm), an ArF excimer laser light source (oscillation wavelength 193 nm), or the like is used. Instead of the excimer laser light source 16, a pulsed light source such as a metal vapor laser light source, a harmonic generator of a YAG laser, or a mercury lamp is used. A secondary light source may be used. The average value of energy per pulse of the excimer laser source 16 is usually the force stabilized at a given center energy E.

0

The average value of Rugi is a predetermined variable range above and below its energy E (for example, about 10%

0

It is configured so that it can be controlled in degrees. The beam shaping optical system 18 shapes the cross-sectional shape of the laser beam LB pulsed by the excimer laser light source 16 so that it efficiently enters the fly-eye lens 22 provided behind the optical path of the laser beam LB. For example, it is composed of a cylinder lens, a beam expander (both not shown), and the like. The energy coarse adjuster 20 is arranged on the optical path of the laser beam LB behind the beam shaping optical system 18, and here, a plurality of different transmittances (= 1−attenuation rate) around the rotating plate 34 ( For example, six ND filters (two ND filters 36A and 36D force S are shown in Fig. 7) are arranged, and the rotating plate 34 is rotated by the drive motor 38 to make the incident. The transmissivity for the laser beam LB can be switched from 100% in multiple steps in a geometric series. The drive motor 38 is controlled by the main controller 50. The fly-eye lens 22 is arranged on the optical path of the laser beam LB emitted from the energy coarse adjuster 20, and forms a large number of secondary light sources for illuminating the reticle R with a uniform illuminance distribution. In the following, this laser light beam that also emits the secondary light source power is called illumination light IL.

In the vicinity of the exit surface of the fly-eye lens 22, an illumination system aperture stop plate 24 that also serves as a disk-shaped member is disposed. The illumination system aperture stop plate 24 has an equal angular interval, for example, an aperture stop composed of a normal circular aperture, an aperture stop composed of a small circular aperture, an aperture stop for reducing the coherence factor σ value, and annular illumination. A ring-shaped aperture stop, and a modified aperture stop in which a plurality of apertures are eccentrically arranged for the modified light source method (only two of these aperture stops are shown in FIG. 7). Has been placed. The illumination system aperture stop plate 24 is rotated by a drive device 40 such as a motor controlled by the main control device 50, so that one of the aperture stops is selectively placed on the optical path of the illumination light IL. Set to A beam splitter 26 having a low reflectance and a high transmittance is arranged on the optical path of the illumination light IL emitted from the illumination system aperture stop plate 24, and further, a reticle blind 30 is interposed on the optical path behind this. The relay optical system consisting of 1 relay lens 28 and 2nd relay lens 29 Has been placed.

[0062] The reticle blind 30 includes a fixed blind and a variable blind. The fixed blind is arranged on a surface slightly defocused with respect to the pattern surface of the reticle R, and defines an illumination area 42R on the reticle R. A rectangular opening is formed. In addition, the variable blind in the reticle blind 30 forms an opening having a variable position and width in the scanning direction, and the opening further has a leading edge and a trailing edge in the scanning direction at the start and end of scanning exposure, respectively. The position of the direction of the arrow in the figure is controlled by the main controller 50 via the drive unit 31 to prevent exposure of an unnecessary part on the reticle R.

[0063] Further, an integrator sensor 46 including a condenser lens 44 and a photoelectric conversion element is disposed on a reflected light path by the beam splitter 26 in the illumination system 12. Illumination light IL reflected by the beam splitter 26 is received by the integrator sensor 46 through the condenser lens 44, and the photoelectric conversion signal force of the integrator sensor 46 is not shown. And is supplied as an output DS (digit / pulse) to the main controller 50 (arithmetic unit for calculating the integrated exposure amount). The correlation coefficient between the output DS of the integrator sensor 46 and the pulse energy (exposure amount) per unit area of the illumination light IL on the surface of the wafer W is obtained in advance and stored in the main controller 50. Has been.

[0064] After passing through the first relay lens 28, the illumination light IL that has passed through the rectangular opening of the reticle blind 30 passes through the second relay lens 29, is reflected by the beam splitter 13, and passes through the condenser lens 37. Thus, the reflecting mirror 11 is illuminated with a uniform illumination distribution. The reflected light from the reflecting mirror 11 passes through the condenser lens 37, the beam splitter 13, the aperture 55a of the light shielding member (which may be a light absorber) 55 as the diaphragm member, and the condenser lens 32 to reach the reticle R again. Illuminate the illumination area 42R uniformly. Also, mirror elements (reflective elements) similar to the mirror elements of the digital micromirror device used in the first embodiment are matrixed in the elongated ridge regions at both ends corresponding to the scanning direction of the reticle R of the reflective mirror 11. The mirror element parts D1 and D2 arranged in a shape are arranged. Mirror element parts Dl, D2 and the substrate on the back, and force Digital micromirror device (DMD) as a reflective element array It is made. The mirror elements Dl and D2 are in the ON state where the tilt angle of the reflecting surface is 0 ° (first reflection direction) and other predetermined angles (first 2), the illumination light reflected when the mirror elements are in the on state passes through the opening 55a of the light shield 55, and the mirror elements are turned off. The illumination light IL reflected in the state is shielded by the light shield 55.

[0065] At this time, the movable blind of the reticle blind 30, the reflecting surface of the reflecting mirror 11, and the pattern surface of the reticle R are arranged at optically conjugate positions. In some cases, it is better to have a gradient of the exposure dose distribution at the edge of the lighting area 42R in the direction of travel. For this case, the position of the fixed blind of the reticle blind 30 is determined from its conjugate position. It is placed at a slightly defocused position.

Here, projection optical system PL is composed of a plurality of lens elements arranged so as to have a bilateral telecentric optical arrangement. The projection magnification | 8 of the projection optical system PL is a reduction magnification of 1Z4, 1Z5, etc., for example. When the illumination region 42R on the reticle R is illuminated by the illumination light IL as described above, an image obtained by reducing the pattern in the illumination region 42R formed on the reticle R by the projection optical system PL with the projection magnification β ( A partially inverted image is formed in a slit-shaped exposure region 42W conjugate with the irradiation region 42R on the wafer W having a photoresist (photosensitive material) coated on the surface. Hereinafter, the horizontal axis is taken parallel to the optical axis of the projection optical system PL, the X axis is taken in the direction perpendicular to the paper surface of FIG. 7 in the plane perpendicular to the Z axis, and the Y axis is parallel to the paper surface of FIG. Take and explain. Here, the XY plane is almost horizontal. The direction parallel to the Y axis (Y direction) is the scanning direction SD of the reticle R and wafer W during scanning exposure, and the direction perpendicular to the X axis (X direction) is the non-scanning direction perpendicular to the scanning direction NSD. It is.

[0067] Reticle R is sucked and held on reticle stage RST. Reticle stage RST can be finely driven in the XY plane, and is scanned within a predetermined stroke range in the scanning direction (Y direction) by reticle stage driving unit 48. The position of reticle stage RST during scanning is measured by an external laser interferometer 54R through a movable mirror 52R fixed on reticle stage RST, and the measured value of laser interferometer 54R is measured by main controller 50R. To be supplied.

[0068] Further, the wafer W is sucked and held on the Z tilt stage 58 via a wafer holder (not shown). The Z tilt stage 58 is mounted on the XY stage 14. The heel stage 14 is two-dimensionally driven on a wafer base (not shown) by a wafer stage driving unit 56 in the heel direction which is the scanning direction in the heel surface and in the X direction perpendicular thereto. The Ζ tilt stage 58 has a function of adjusting the position (focus position) in the Ζ direction on the wafer W and adjusting the tilt angle of the wafer W with respect to the ΧΥ plane. The position of the stage 14 (wafer W) is measured by an external laser interferometer 54W (position detection device) via a movable mirror 52W fixed on the tilt stage 58. The measured value is supplied to the main controller 50.

[0069] In addition, an illuminance unevenness sensor 59 that also has photoelectric conversion element force is permanently installed in the vicinity of the wafer W on the tilt stage 58, and the light receiving surface of the illuminance unevenness sensor 59 is set to the same height as the surface of the wafer W. Has been. The detection signal of the illuminance unevenness sensor 59 is supplied to a main controller 50 functioning as an exposure controller via a peak hold circuit (not shown) and an AZD change. The main controller 50 is configured to include a computer and controls, for example, synchronous scanning of the reticle R and the wafer W, stepping of the wafer W, exposure timing, and the like so that the exposure operation is performed accurately. In the present embodiment, the main controller 50 also performs exposure amount control during scanning exposure described later.

[0070] Specifically, main controller 50, for example, during scanning exposure, synchronizes with reticle R being scanned at speed V in the + Y direction (or -Y direction) via reticle stage RST.

R

The wafer W is scanned through the XY stage 14 with respect to the exposure area 42W — in the Y direction (or + Y direction) at a velocity β · ν (β is the reticle R to the wafer, and the projection magnification for W).

R

In addition, the position and speed of reticle stage RST and XY stage 14 are controlled via reticle stage drive unit 48 and wafer stage drive unit 56, respectively, based on the measurement values of laser interferometers 54R and 54W. Further, at the time of stepping, main controller 50 controls the position of XY stage 14 via wafer stage drive unit 56 based on the measurement value of laser interferometer 54W.

Further, main controller 50 controls the light emission power and the like of excimer laser light source 16 by supplying control information TS to excimer laser light source 16. In addition, the main control device 50 includes an energy coarse adjuster 20 and an illumination system aperture stop plate 24 for a motor 38 and a drive device, respectively. Further, the opening / closing operation of the movable blind in the reticle blind 30 is controlled via the driving device 31 in synchronization with the operation information of the stage system. Thus, in this example, it also serves as the main controller 50 force exposure controller and stage controller. Of course, these controllers may be provided separately from the main controller 50. The main controller 50 is connected with a storage device 51 and an input / output device 62 such as a console. As in the first embodiment, the storage device 51 stores information on an exposure amount map and a correction map indicating the appropriate exposure amount for each partial region of the reticle R.

Here, the reflection mirror 11 that is a feature of this example will be described. The reflecting mirror 11 includes a portion where a dielectric multilayer film or an aluminum thin film is formed on the surface (reflecting surface) of the substrate having a high flatness in order to reflect the illumination light IL well, and the surface along the surface. In this way, two mirror element parts Dl and D2 in which a plurality of mirror elements of a digital micromirror device (DMD) are arranged are provided. The individual mirror elements of the mirror element portions Dl and D2 are driven by the main controller 50 via the DMD driving device 33.

[0073] It should be noted that mirror elements similar to the mirror element portions Dl and D2 may be arranged on the entire reflecting surface of the reflecting mirror 11, but for the exposure control, the entire area is not necessarily limited to mirror elements. There is no need. Further, instead of the mirror element parts Dl and D2, one mirror element part may be provided, or three or more mirror element parts may be provided.

FIG. 8 shows the conjugate relationship between the reflecting mirror 11 and the illumination area 42R on the reticle R. In FIG. 8, the reflecting mirror 11 is a perspective view of the back surface force of the reflecting surface. In addition, each point of the reflection mirror 11 and the corresponding point (almost conjugate point) of the illumination area 42R are inverted vertically and horizontally as shown schematically using a virtual letter "F". Corresponds to 1: 1. As shown in FIG. 8, the mirror element parts Dl and D2 are arranged in a line along the non-scanning direction at both end positions in the scanning direction on the reflecting surface of the reflecting mirror 11, and the reflected light is the illumination area of the reticle R. The position corresponding to the edge R1 or edge R2 in the scanning direction of 42R is irradiated. Edges R1 and R2 are the leading edge and the trailing edge, respectively, if the scanning direction of reticle R is the Y direction, and the trailing edge if the scanning direction of reticle R is the + Y direction (direction SD (+)). And the front edge.

[0074] As shown in the perspective view of FIG. 9, both the mirror element portions D1 and D2 are driven by the reflecting mirror 11. Edge force in the heel direction (Y direction) is also n lines in the scanning direction (each line is dl, dl,.

1 2 n and d2, d2,---d2), m columns in the non-scanning direction (X direction) (each column is 1, 2, ...,

1 2 n

m)), n × m mirror elements are arranged in a matrix. n and m are arbitrary integers of 1 or more.

At this time, the number (n) of mirror elements in the scanning direction does not have to be the number that can illuminate the entire scanning direction of the illumination region 42R, but the number (m) of mirror elements in the non-scanning direction It is desirable to set the number to be able to irradiate the entire area of the area 42R in the non-scanning direction.

Here, in FIG. 8, for example, the mirror element of portion A in the mirror element portion D1 (corresponding to a plurality of adjacent mirror elements in FIG. 8) is turned off (tilt) by the DMD driving device 33 of FIG. The light reflected by the mirror element force of part A (shown by the alternate long and short dash line) is a light-shielding body (or absorption element) placed at the pupil position of the illumination system between the condenser lens 37 and the condenser lens 32. (It may be a body.) Light is blocked at 55, and no illumination light enters the conjugate position A 'on the reticle R. If the mirror element in part A is turned off between times ta and tb during scanning exposure, the exposure amount of area B on the reticle is reduced compared to other areas. Naturally, the exposure amount of the area on the wafer W corresponding to the area B also decreases. This is because the width in the scanning direction of the exposure area of this portion is substantially reduced, and the amount of exposure that decreases as the number of mirror elements that are turned off (the number of rows) along the scanning direction increases. . In order to accurately separate the region on the reticle R or the wafer W where the amount of light is to be reduced from the V and region that are likely to be reduced, the reflecting mirror 11 is placed at a position optically conjugate with the reticle R. Although it is necessary, the reflecting mirror 11 may be slightly shifted from the conjugate position so that the mechanical gaps between adjacent mirror elements are not projected as dark lines.

Further, in the storage device 51 of FIG. 7, the exposure amount map in the shot area is stored in advance for each reticle to be used by the operator via the input / output device 62.

FIG. 10 shows an example of an exposure map in the pattern area PA of the reticle R. In FIG. 10, several types of functional circuits are formed in the partial area PT1, PT2, PT3 in the pattern area PA. Assume that the appropriate exposure amounts are set to Dosel, Dose2, and Dose3 (assuming Dosel>Dose2> Dose3). This exposure amount is The data obtained based on the measurement result of the line width distribution of the transfer image of the isolated pattern in the transfer image obtained by transferring the pattern of the reticle R to the shot areas on the wafer W. Desirably, the data should equalize the pattern line width of each shot area (first step). Isolation pattern (for example, isolation line, contact hole pattern) Since it is more sensitive to exposure than a dense pattern, it can be obtained based on the measurement results of the line width distribution of the transfer image of the isolation pattern. In addition, by using the exposure amount that equalizes the pattern line width of each shot area to the desired line width as data, more accurate exposure amount control can be realized and the pattern line width accuracy can be further improved. be able to. The exposure amount in the same shot determined in this way is expected to be set in a range where the average exposure amount is increased or decreased by several% to 10%.

Hereinafter, the steps of scanning and exposing the photoresist on the wafer W in FIG. 7 using the reticle R having the pattern shown in FIG. 10 will be described in order. Here, in the scanning exposure in which all the mirror elements of the mirror element portions Dl and D2 of the reflecting mirror 11 are in the ON state (the entire illumination area 42R is irradiated with the illumination light IL), the exposure amount irradiated to the photoresist Is selected as the ND filter of the energy coarse adjuster 20 and at least one of the adjustment of the emission power of the excimer laser light source 16 so that Dosel is the largest appropriate exposure dose in the pattern area. Assume that the strength is adjusted.

[0078] In FIG. 11 showing reticle R during scanning, illumination region 42R at time t

0

Is in the positional relationship shown in position B1. In an actual scanning exposure apparatus, the illumination area 42R does not move, and the reticle R is scanned with the movement of the reticle stage. In FIG. 11, the illumination area 42R is moved for convenience, and the pattern of the reticle R The positional relationship with area PA shall be indicated. At this time, one movable blind of the reticle blind 30 in FIG. 7 corresponding to the trailing edge of the scanning direction SD (—) is closed and the pattern area PA (that is, the corresponding shot area SA on the wafer W) is closed. The outer peripheral area is not exposed. When the movable blind that was closed in synchronization with the start of scanning is opened, the partial area PT1 is first exposed, and when the illumination area 42R is completely in the pattern area PA, the movable blind is fully open. Scanning exposure in this state is performed until time t when the leading edge 42RF of the illumination area 42R reaches the end (position B2) of the partial area PT1. [0079] As shown in FIG. 12, at the time t when the front edge of the illumination area 42R reaches the partial area PT2.

1

D1 of mirror element D1 of reflection mirror 11

1 to d P rows of mirror elements sequentially, P

The entire area in the non-scanning direction (all m columns) is turned off (with tilt) so that the reflected light from the mirror elements in the P row is not projected onto the partial area PT2 in FIG. In FIG. 12 (the same applies to FIGS. 13 and 14), the mirror element Md in the off state is shaded. In FIG. 12, the number of rows P of the mirror elements to be turned off is determined so that the integrated exposure amount of the partial region PT2 becomes Dose2. Specifically, as described above, the exposure amount is set to Dose 1 when all the mirror elements are in the on state! Therefore, the width in the scanning direction of the illumination area 42R at this time is set to L If so, the width in the scanning direction should be LX (Dose2 / Do sel). Therefore, the width of the mirror element with the number of rows P is determined to be L X (1—Dose2ZDosel). In FIG. 11, when the rear edge of the illumination area 42R reaches the boundary between the partial areas PT1 and PT2, the exposure of the partial area PT1 is completed, and the partial area PT1 is exposed by Dosel.

[0080] Thereafter, the front edge of the illumination area 42R (more precisely, the reflection from the mirror element in the dl row)

P + i

Mirror element section until time t when the area exposed to light reaches partial area PT3 (position B3)

2

Exposure is performed with the mirror elements in the P1 rows from D1 to D1 being off. And time t

At 1 p 2, as shown in FIG.

Mira Q in the row of P + l ~ dl

One element is turned off sequentially. These columns l to r correspond to the number of mirror elements that irradiate the width X3 of the partial region PT3 in FIG. 11 in the non-scanning direction. The width of the mirror element with the number of rows Q is determined to be L X (l—Dose3ZDosel) as described above. In this way, scanning exposure is performed until time t when the trailing edge of the illumination area 42R in FIG. 11 reaches the end of the pattern area PA.

Three

As with the start of scanning, one of the reticle blinds 30 corresponding to the front edge in the scanning direction is not exposed so that the outer peripheral area of the pattern area PA (that is, the shot area SA on the wafer W) is not exposed. The movable blind is closed in synchronization with the scan.

In the above description, the force described with reference to the case where the exposure amount of the pattern area to be scanned becomes smaller as the scanning exposure progresses may be Dose3> Dose2. In such a case, at the time t in FIG. Of these, dl in rows l to r in Fig. 14

If the mirror elements in rows p to dl are turned on sequentially, p

Good. The width of the mirror element with the number of rows P—S is determined to be L X (1—Dose3ZDosel) as described above. Alternatively, a part of the mirror element part D2 disposed at the rear edge of the illumination area 42R is turned off in advance, and when the rear edge reaches the boundary between the partial areas PT2 and PT3, the mirror element part D2 Make sure to turn on the columns to irradiate the partial area PT3 with the required number of rows.

Through the above steps, exposure of one shot area on the wafer W is completed, and exposure is performed with an optimum exposure amount for each partial area on the reticle R (second process). In a scanning type exposure apparatus, when performing exposure of the next shot area, it is general to perform scanning exposure in a direction opposite to the scanning direction of the immediately preceding shot area. In this case, the mirror element part D1 described above may be operated by replacing it with the mirror element part D2 corresponding to the front edge part in the scanning direction.

In addition, the storage device 51 in FIG. 7 cancels the fluctuation component of the line width caused by the device manufacturing process such as non-uniformity of the coating thickness of the photosensitive material on the wafer and non-uniformity at the time of development. The corrected exposure amount for this is stored as a correction map for each position on the wafer.

As shown in FIG. 15 (a), this corrected exposure dose is generally distributed concentrically (or elliptically) from the center of the wafer W. In Fig. 15 (a), the first, second, or higher order function of the distance from the force center indicates that a larger exposure is required in proportion to the distance of the center force. It may become. For example, the operator may input a function of the distance of the central force to the input device 62 in FIG. 7 so that a correction map is set in the storage device 51 for each position of each shot area SA. For example, the correction map of the shot area SA whose center coordinate is (X, y) is calculated from the input function and the shape of the shot area SA, and is generated as shown in FIG.

[0084] Similar to the operation described with reference to FIGS. 11 to 14, the mirror of the reflecting mirror 11 of FIG. 7 in the positional relationship between the illumination area 42R and the shot area SA according to the correction map of FIG. If the mirror element of the single element portion D1 or D2 is driven, exposure can be performed with an exposure amount to compensate for the line width error caused by the device manufacturing process.

In addition, the storage device 51 in FIG. 7 has illumination in the non-scanning direction caused by the exposure device (illumination system 12). Data for correcting degree uniformity is also stored. The force that is desired to be uniform in the exposure area is not necessarily uniform in the light quantity distribution of the shot area SA on the wafer.

[0085] For example, as shown in FIG. 16 (a), the illumination distribution in the exposure area IA on the shot area SA of the wafer is a distribution in which the illuminance IIL decreases as the illumination intensity increases toward the center. And At this time, the integrated exposure amount ΣΕ on the wafer by scanning exposure has a distribution as shown in FIG. 16 (b) in which the illuminance in the scanning direction SD is integrated for each point in the non-scanning direction NSD. In other words, the integrated exposure dose distribution in the scanning direction SD is flattened by scanning, but the non-uniformity of the integrated exposure dose distribution in the non-scanning direction NSD is not eliminated. As a method of solving this, as shown in Fig. 17 (a), the width of the exposure area IA on the wafer shot area SA is adjusted in the scanning direction SD for each position in the non-scanning direction NSD. It should be uniform as shown in Fig. 17 (b). The illumination unevenness correction map is obtained by using the width in the scanning direction of the shot area for each position in the non-scanning direction NSD, and the illumination unevenness correction map is also stored in the storage device 51 of FIG.

[0086] In this case, the shape of the illumination region 42R is changed to ON / OFF of one of the mirror elements D1 or D2 (or both of them) of the reflecting mirror 11 of FIG. The exposure area (b) may be the same shape as the IA. It is known that the illuminance uniformity of the exposure apparatus changes over time depending on the exposure conditions, and in the method of this example, the shape of the illumination area 42R can be arbitrarily changed. It can be easily corrected.

In this example, as described above, the exposure operation according to the representative three types of data stored in the storage device 51 of FIG. 7 has been described independently. Corrective correction (superimposition correction) is also possible. Further, the exposure amount control for each shot area may be performed without using the correction map as described above.

In the above embodiment, as shown in FIG. 7, the case where the reflecting mirror 11 has the two mirror element portions D1 and D2 has been described. However, the mirror element portion may be provided only on one side. In the scanning exposure apparatus, a technique may be used in which the illumination distribution on the front edge and the rear edge of the illumination area 42R is intentionally inclined to increase the accuracy of exposure uniformity. In such a case, as shown in FIG. It is good as a configuration arranged in the center of the direction.

FIG. 18 shows a modification of the scanning exposure apparatus of FIG. 7. In FIG. 18, in which parts corresponding to those of FIG. 7 are given the same reference numerals, the rectangular blind part 30 of the reticle blind 30 is passed. The illumination light IL passes through the second relay lens 29 and illuminates the reflection mirror 11 disposed at an inclination of 45 ° with respect to the optical axis through the condenser lens 49 with a uniform illumination distribution. The downward reflected light from the reflection mirror 11 passes through the condenser lens 42, the opening of the light shield 55, and the condenser lens 32, and uniformly illuminates the illumination area 42R on the reticle R. Further, a mirror element portion D3 similar to the mirror element portion D1 in FIG. Each mirror element of the mirror element part D3 is in the ON state where the tilt angle of the reflecting surface is 0 ° (first reflection direction) and other predetermined angles (second The illumination light reflected when the mirror elements are in the on state passes through the opening of the light shield 55 and the mirror elements are in the off state. The illumination light IL reflected at this time is shielded by the light shield 55. The mirror element D3 is also controlled by the DMD driving device 33. The other configuration is the same as that of the scanning exposure apparatus of FIG.

In FIG. 18, it is not necessary to arrange all the reflection regions of the reflection mirror 11 at positions optically conjugate with the reticle R. The center of the reflection mirror 11 having the mirror element D3 is the pattern surface of the reticle R. Since the reflecting mirror 11 may be arranged so as to be conjugate, there is an advantage that the arrangement of the optical system is simplified.

FIG. 19 shows the conjugate relationship between the reflection mirror 11 of the scanning exposure apparatus of FIG. 18 and the illumination area 42R on the reticle R. In FIG. 19, the mirror element portion D3 in the reflection mirror 11 is the same as the reticle R. Therefore, the reflected light irradiates the position corresponding to the center portion in the scanning direction of the illumination area 42R on the reticle R. The mirror element D3 has n rows in the scanning direction (each row is d3, d3,--· ά3) and m columns in the non-scanning direction (each row is 1, 2,… !!

1 2 n

N x m mirror elements are arranged in a matrix. Here, for example, the mirror element of the central portion C in the mirror element portion D3 (corresponding to a plurality of adjacent mirror elements in FIG. 19) is turned off (tilted) by the DMD driving device 33 in FIG. , The reflected light of the mirror element force turned off (indicated by the dotted line) The light is shielded by a light shield 55 (or an absorber) 55 disposed at the optical pupil position between the lens 14 and the condenser lens 32, and the illumination light does not reach the conjugate position C ′ on the reticle R. Not irradiated.

[0090] Temporarily, at the start time t of scanning exposure, all mirror elements are turned on (not tilted)

0

If the mirror element in part C is turned off between time ta and tb, the amount of exposure in area E on reticle R decreases compared to other areas. Naturally, the exposure amount of the area on the wafer W corresponding to the area E also decreases. This is because the width in the scanning direction of the exposed area 42W of this portion decreases, and the amount of exposure that decreases as the number of mirror elements that are turned off increases in the scanning direction increases. In addition, in order to accurately separate the area where the exposure amount on reticle R or wafer W is reduced from the ridge area which is likely to be, the reflecting mirror 11 is arranged at a position optically conjugate with reticle R. Although it is necessary, in the configuration shown in FIGS. 18 and 19, the mirror element portion D3 is arranged almost at the conjugate position with the conjugate position as the center.

FIGS. 20 (a) and 20 (b) are graphs of the illuminance IIL distribution in the illumination area 42R in the configuration of FIG. 18 with the scanning direction SD as the horizontal axis. The illuminance distribution when all the mirror elements of the mirror element portion D3 of the reflecting mirror 11 are in the on state is almost flat as shown in FIG. On the other hand, the illuminance distribution when all of the mirror elements in the mirror element D3 are in the OFF state is the force at which the illuminance IIL near the center is 0 as shown in Fig. 20 (b). The slope of the illuminance distribution at the trailing edge is maintained. As a result of scanning exposure, the integrated exposure amount of each point on the photoresist on the wafer W corresponds to the area (integrated value) of the illuminance distribution graph in FIG. 20 (a) or FIG. 20 (b). It can be easily understood that the greater the number of rows of mirror elements that are turned off, the smaller the integrated exposure. Since the difference between the largest exposure to be irradiated and the smallest exposure in a shot area is considered to be about 10%, the mirror elements in all rows are turned on for normal exposure control. It is sufficient to provide the number of rows of mirror elements so that the area is reduced by 10% with respect to the area of the graph.

In the second embodiment described above, the force interferometer 54R (or the interferometer 54W) is configured to control the mirror element elements Dl, D2, D3 based on the time during the scanning of the reticle R. The mirror element units Dl, D2, and D3 may be controlled based on the values. As described above, according to this example, it is possible to perform exposure with an optimum exposure amount for each local area in the shot area in accordance with the characteristics of the pattern transferred in the shot area. In addition, it is possible to correct pattern line width errors caused by uneven application of photoresist and uneven development, and it is also possible to correct illuminance non-uniformity caused by an exposure apparatus (such as illumination system 12). In each of the above-described embodiments, the case where the reduction system is used as the projection optical system has been described. However, the present invention is not limited to this, and the projection optical system may be an equal magnification or an enlargement system. Either a system or a reflection system may be used.

[0093] Further, for example, for a semiconductor device, a step of performing functional / performance design of the device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, It is manufactured through a step of transferring a reticle pattern to a wafer by a projection exposure apparatus (exposure apparatus), a device assembly step (including a dicing process, a bonding process, a knocking process), and an inspection step.

The present invention can also be applied to the case where exposure is performed with an immersion type exposure apparatus disclosed in, for example, International Publication No. 99/49504 pamphlet. The present invention can also be applied to an exposure apparatus that uses extreme ultraviolet light (EUV light) having a wavelength of about 1 to 1 OO nm as an exposure beam. Although the optical system using EUV light is a reflection type, the reflection element array of the present invention is a reflection type optical member and can be used as it is for EUV light.

Further, the present invention is not limited to an exposure apparatus for manufacturing a semiconductor device, but is used for manufacturing a display including a liquid crystal display element, a plasma display, etc., and an exposure apparatus for transferring a device pattern onto a glass plate, a thin film Devices used for manufacturing magnetic heads Applicable to exposure devices that transfer non-turns onto ceramic wafers, and exposure devices used to manufacture image sensors (CCDs, etc.), organic EL, micromachines, DNA chips, etc. be able to. In addition, a circuit on a glass substrate or a silicon wafer is used to manufacture a mask used in a light exposure apparatus, EUV exposure apparatus, X-ray exposure apparatus, electron beam exposure apparatus, and the like, which are formed only by microdevices such as semiconductor elements. The present invention can also be applied to an exposure apparatus that transfers a pattern.

[0096] In the above-described embodiment, force using a light-transmitting mask in which a predetermined light-shielding pattern (or phase pattern 'dimming pattern') is formed on a light-transmitting substrate. Instead of a mask, an electronic mask that forms a transmission pattern or a reflection pattern based on electronic data of a pattern to be exposed, for example, as disclosed in US Pat. No. 6,778,257, may be used. ,.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be taken without departing from the gist of the present invention. In addition, the entire disclosure of Japanese Patent Application No. 2005-0335383 filed on February 14, 2005, including the description, claims, drawings, and abstract, is incorporated herein by reference in its entirety. And

Industrial applicability

According to the present invention, since it is possible to perform exposure with an optimum exposure amount for each of a plurality of local regions, it is possible to improve the line width uniformity of a pattern image exposed on an object. Therefore, a device in which a plurality of circuits are integrated into one chip can be manufactured with high accuracy and high yield.

Claims

The scope of the claims

[1] In an exposure apparatus that exposes an object with an exposure beam from a light source,

A plurality of reflecting elements each capable of controlling a reflection direction of the exposure beam, and a reflecting element disposed between the light source and the object for adjusting an illuminance distribution in an illumination area of the exposure beam on the object An array,

A storage device storing exposure amount control data for controlling the exposure amount of the object;

An exposure apparatus comprising: a control device that controls the reflective element array based on the exposure amount control data stored in the storage device.

[2] The exposure apparatus according to claim 1, wherein the reflective element array has a digital micromirror device force.

[3] Each reflecting element constituting the reflecting element array reflects the exposure beam in one of the first and second reflecting directions,

2. The beam splitter according to claim 1, further comprising: a beam splitter that guides the exposure beam from the light source to the reflection element array; and a diaphragm member that blocks the exposure beam reflected in the second reflection direction. 2. The exposure apparatus according to 2.

[4] The exposure amount control data is set so that a line width distribution of a pattern image formed on the object is a predetermined distribution. The exposure apparatus described.

[5] The object is a substrate coated with a photoreceptor,

The exposure amount control data is set so as to correct at least one of a non-uniformity in coating thickness of the photosensitive member and a non-uniformity in development characteristics depending on a position on the substrate. The exposure apparatus according to any one of 1 to 4.

[6] The reflective element array is disposed at a position substantially conjugate with the object between the light source and the object, or at a position shifted by a predetermined amount of the conjugate force of the conjugate. The exposure apparatus according to any one of claims 1 to 5, wherein

[7] The apparatus further includes an arithmetic unit for obtaining an integrated exposure amount of the exposure beam for the object during the exposure of the object, 7. The deviation according to claim 1, wherein the control device controls the reflective element array based on an integrated exposure amount obtained by the arithmetic device and the exposure amount control data. Exposure equipment.

8. The exposure apparatus according to any one of claims 1 to 7, wherein the exposure apparatus is a scanning exposure type that moves the object with respect to the exposure beam during exposure of the object. .

[9] The apparatus further comprises a position detection device that measures position information in the scanning direction of the object,

The exposure apparatus according to claim 9, wherein the control apparatus controls the reflective element array based on position information obtained by the position detection apparatus and the exposure amount control data.

[10] The exposure amount control data is set such that an integrated light amount value in the scanning direction of the illumination area of the exposure beam is substantially uniform in a non-scanning direction orthogonal to the scanning direction. An exposure apparatus according to claim 8 or 9.

[11] The reflective element array includes a plurality of reflective elements arranged in one or a plurality of lines in a region corresponding to a predetermined position in the scanning direction of the illumination region of the exposure beam. The exposure apparatus according to any one of claims 8 to 10.

[12] The exposure according to any one of [8] to [11], wherein the control device controls the width of the illumination region of the exposure beam in a scanning direction by controlling the reflective element array. apparatus.

13. The exposure apparatus according to any one of claims 1 to 12, wherein the exposure amount control data is set for each of a plurality of partitioned regions on the object.

14. The control device according to claim 1, wherein the illuminance distribution in the illumination area is changed based on the exposure amount control data during exposure of one section area on the object. The exposure apparatus according to claim 13.

15. The object according to claim 1, wherein the object is exposed by illuminating a mask on which a predetermined pattern is formed with the exposure beam having the reflection element array force and projecting an image of the pattern of the mask onto the object. 15. The exposure apparatus according to any one of 14 to 14.

[16] It is disposed between the light source and the mask, and the exposure beam from the light source is uniformly illuminated. 16. The exposure apparatus according to claim 15, further comprising an optical integrator that is incident on the reflective element array with a degree distribution.

[17] An exposure method for exposing an object by irradiating the object with an exposure beam from a light source, for controlling at least one of an exposure amount and an exposure amount distribution for each of a plurality of partitioned regions on the object A first step for obtaining exposure control data;

Using a reflective element array that is disposed between the light source and the object and includes a plurality of reflective elements each capable of controlling the reflection direction of the exposure beam,

And a second step of controlling an illuminance distribution in an illumination area of the exposure beam on the object based on the exposure amount control data.

18. A device manufacturing method using the exposure apparatus according to any one of claims 1 to 16.