WO2001038602A1

WO2001038602A1 - Compound vapor spraying device and focusing ion beam device using it

Info

Publication number: WO2001038602A1
Application number: PCT/JP2000/008028
Authority: WO
Inventors: Yoshihiro Koyama; Toshiaki Fujii; Tadashi Kawashima; Masamichi Oi
Original assignee: Seiko Instruments Inc.
Priority date: 1999-11-22
Filing date: 2000-11-14
Publication date: 2001-05-31
Also published as: TW476978B; JP4350333B2

Abstract

A compound vapor spraying device used in a focusing ion beam device, capable of handling safely a compound vapor material, wherein a compound vapor-filled container (32) is mounted on a compound vapor material container (31) having an injection needle-shaped guide (45) passing through part of the container (32) and introducing the compound vapor to a sample room of the focusing ion beam device.

Description

Description Compound vapor spray device and focused ion beam device using the same

The present invention relates to a focused ion beam apparatus for irradiating a focused ion beam while spraying a compound gas onto a sample surface to form a thin film or perform an etching process, and a compound vapor spray apparatus used for the focused ion beam apparatus. Background art

The focused ion beam device scans the sample surface with the focused ion beam, detects secondary electrons and secondary ions generated from the sample surface, and can observe the sample surface enlarged from the distribution. In addition, the focused ion beam is scanned on the sample surface, and the sample surface can be subjected to sputter etching. At this time, gas assist etching can be performed in which etching is performed while simultaneously spraying compound vapor onto the sample surface. When gas assisted etching is performed, the combination of the compound vapor and the sample material is used to perform etching that is faster in processing speed than normal sputter etching, or to perform selective etching using the fact that the etching speed changes depending on the sample material. be able to. In addition, a compound vapor, which is a raw material of the thin film, is introduced into the sample chamber, and a focused ion beam is scanned on the sample surface while being sprayed on the sample surface, thereby performing a deposition process for forming a thin film on the sample surface. As described above, it is effective to introduce a compound vapor into a sample chamber of a focused ion beam apparatus. Therefore, an apparatus for spraying some compound vapor onto a sample surface has been proposed. For example, JP-A-61-12864 discloses the most basic structure for spraying a compound vapor onto a sample. The compound vapor raw material is stored in a container, a valve is provided in the middle of the pipe connecting the sample chamber in which the sample is placed, and spraying of the compound vapor onto the sample surface is controlled by opening and closing the valve. Japanese Patent Application Laid-Open No. 11-185691 discloses a structure of a container and a reservoir for storing a compound vapor raw material. In the above-mentioned JP-A-11-185691, the compound vapor raw material is generally in the form of a powder, and it is indicated that the powder is packed in a reservoir, and the container "reservoir" filled with the powder as the compound vapor raw material is compounded. Issues and solutions for mounting it on a steam blower or “gas gun” are shown. The challenge presented here is that the powder, which is the compound vapor source, spills around the reservoir, and the solution is to always open the reservoir opening for filling the compound vapor source, facing the sky. As shown in the figure, a structure for maintaining the reservoir posture is shown. However, it is obvious that preventing the compound vapor raw material from spilling out of the reservoir having such a normally open opening cannot be realized only by the posture of the reservoir.

Also, since there are a wide variety of applications for focused ion beam devices, there are many types of compound vapors to be used. Therefore, the state of the compound vapor raw material at room temperature may be not only powder but also solid or liquid. In addition, those with very low vapor pressure and easy to vaporize are also conceivable. Furthermore, due to their chemical properties, some may be harmful to the human body or the environment, and others may be highly flammable and highly dangerous. In this way, a wide variety of compound vapor raw materials can be It is difficult to handle in one reservoir. In addition, special equipment is required for refilling work. Disclosure of the invention

The present invention relates to a compound vapor spraying device attached to a focused ion beam device that irradiates a focused ion beam to a predetermined position of a sample in an atmosphere in which a compound vapor is present, wherein a compound is stored while shutting off the compound from the atmosphere. A syringe-shaped guide for guiding the compound vapor from the second container to the outside through a part of the second container, and communicating with the guide via an on-off valve, and It has a nozzle for spraying a compound vapor to a predetermined position, and a first container for accommodating the second container. In addition, there is provided a sample chamber provided between the opening / closing valve and the nozzle for mounting the sample, or a second valve connected to one or all of a plurality of sample chambers. .

Further, the nozzle is characterized in that it communicates with other compound vapor spraying devices via respective opening / closing valves.

Further, the second container is characterized in that it has a structure in which the inside can be seen, and the second container is characterized by being made of a material having good heat conductivity.

In the first container, the guide portion is attached to a lid, and when the second container is stored therein and the lid is closed, the inside of the case is inserted into the lid of the second container. It is characterized in that the second container can be taken out of the first container by lifting the lid of the first container. Further, a temperature control system is provided, which controls the temperature of the first container so that the amount of the compound vapor generated in the compound contained in the second container becomes a predetermined amount. I have.

Further, the guide, the nozzle and the valve communicate with each other by a pipe, and the pipe is controlled in temperature.

Further, the temperature of the nozzle is controlled. Further, the guide section is temperature-controlled. Further, the second container has a seal, seals the compound, and penetrates the seal with the injection needle-shaped guide.

Also, it is characterized in that at least one such compound vapor spraying device is installed. BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is an illustration of a focused ion beam column

Figure 2 shows an example of a focused ion beam device.

FIG. 3 is an explanatory diagram of the present invention.

FIG. 4 is an explanatory diagram of the present invention.

FIG. 5 is an explanatory diagram of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows an example of a focused ion beam column used in the present invention.

The focused ion beam column mainly includes an ion source 1, a condenser lens 2, a blanking electrode 3, a movable diaphragm 4, a deflection electrode 5, and an objective lens 6. In addition, although not shown, an optical axis correction electrode, astigmatism correction electrode, etc. There is. Generally, liquid metal gallium is used as the ion source. The liquid metal gallium stored in the gallium reservoir is supplied to the needle-shaped emitter by surface tension. In addition, the gallium reservoir and the emitter can be heated by the filament. An electric field is applied to the emitter part by one or more electrodes, and the gallium accumulated in the emitter part is extracted as an ion beam. The ion beam is accelerated by this electric field because a high voltage of about +30 kV with respect to the ground potential is applied to the emitter. The ion beam is focused by the condenser lens 2 and focused on the sample surface by the objective lens 6. Fig. 1 shows an Einzern-type lens in which high voltage and ground potential are connected to three electrodes, but this is only an example, and other types of lenses may be used. Further, the objective lens 6 is arranged at a position closest to the sample, but the position can be changed according to the required performance and function.

The movable aperture 4 has a plurality of through-holes having different diameters. The aperture control unit 11 controls the position of the through-hole, and the used through-hole is switched. By passing the beam through each through hole, the amount of beam reaching the sample, ie, the sample current, can be changed. Further, the position of the through hole can be adjusted so as to match the center of the ion beam. The blanking electrode 3 can generate a large electric field between the two electrodes. If the same potential, usually the ground potential, is applied to each electrode, the ion beam reaches the sample. However, when a large electric field is generated by applying a signal having a large potential difference to each electrode of the blanking electrode 3, the electron beam is largely deflected, hits a shield such as the movable diaphragm 4, and the ion beam does not reach the sample. . The deflection electrode 5 is composed of at least two pairs of electrodes facing each other, and the trajectory of the ion beam is two-dimensionally controlled by an electric field generated between the electrodes.

A power supply for generating a signal applied to each of these electrodes and the movable diaphragm 4 is controlled by a computer. Further, signals applied to the blanking electrode 3 and the deflection electrode 5 are generated from the scanning signal generator 10. This makes it possible to determine whether or not to irradiate the sample with the ion beam according to the sample irradiation position. The output signal of the detector is input to the scanning signal generator 10 and processed. Observation of the sample surface by detecting the ion beam irradiation position and secondary charged particles generated by ion beam irradiation at the irradiation position with a detector and storing the output signal as an electric signal together Can be. FIG. 2 shows an example of the focused ion beam device according to the present invention. Here, an example is shown in which a plurality of the focused ion beam columns described in FIG.

The first focused ion beam column 21 is installed at a position where the ion beam is vertically incident on the sample 27 installed horizontally. The second focusing ion beam column 22 is installed at different angles. In the example of Figure 2, 60 It is installed at an angled position. And, the center of the ion beam of each focused ion beam column is set to intersect with the surface of the sample 27 placed on the sample stage 26. The sample stage 26 can be moved at least in three axes of horizontal X, Y, and vertical Z. The horizontal X and Y axes are used to observe the sample and determine the processing position. In addition, the Z-axis is required so that the height of the sample surface is always at the intersection of the focused ion beams emitted from the two focused ion beam columns. By setting the height of the sample surface to the intersection of the focused ion beams, the focused ion beam irradiation positions of the two focused ion beam barrels can be made the same on the sample surface. In addition, it can also have an inclined T axis and a rotating R axis. The detector 23 detects secondary charged particles (electrons or ions) generated by irradiating the sample 27 with the focused ion beam.

A thin film is formed by a beam assisted CVD method using a compound vapor spraying device 24 attached to the focused ion beam device. In the beam assisted CVD method, a compound vapor containing a thin film material deposited on a sample surface is used. The compound vapor is sprayed on the surface of the sample 27 by the compound vapor spraying device 24. The compound vapor sprayed on the sample surface adsorbs on the sample surface. When a focused ion beam is irradiated in this state, the compound vapor is decomposed by its kinetic energy. The decomposed gas component is exhausted to the outside of the sample chamber 25 by the vacuum pump 28, and the solid component remains as a thin film on the sample surface. At this time, the focused ion beam performs sputter etching simultaneously with the deposition. Therefore, compound vapor is introduced so that the deposition rate of the thin film is higher than the processing rate of sputter etching. It is necessary to control the dose and the dose of the focused ion beam. The compound vapor introduced into the sample chamber 25 by the compound vapor spraying device 24 is also used as an etching assist gas for improving the processing speed of sputter etching by spraying the sample surface simultaneously with the irradiation of the focused ion beam. good.

Generally, the etching assist gas chemically reacts with the workpiece sputtered by the focused ion beam irradiation to form a molecular gas combined with the workpiece, thereby forming a vacuum pump. As a result, the gas is exhausted out of the sample chamber 25.

Normally, when a sputter etching process is observed microscopically, it is necessary to repeatedly perform the sputter etching process because a workpiece to be processed by the sputter etching process drops on the sample surface and adheres again.

However, by using an etching assist gas, reattachment can be suppressed, so that the processing time by sputter etching can be shortened. Further, in general, since the etching assist gas chemically reacts with a specific substance, it is possible to perform selective etching utilizing the fact that the processing speed is different between a substance which does not react chemically and a substance which does not react. Also, a gas that reacts with a specific sample and suppresses the progress of sputter etching is known. Selective etching using the difference in processing speed depending on the material is possible. Although only one compound vapor spraying device 24 is shown in the figure, a plurality of compound vapor spraying devices may be used so as to properly use a gas according to the purpose.

The sample chamber 25 and the focused ion beam column are evacuated by the vacuum pump 28. I'm concerned. In addition, although not shown, a load lock chamber for loading and unloading a sample without setting the sample chamber 25 to the atmosphere can be provided. Now, the compound vapor spray device of the present invention shown in FIG. 3 will be described. The compound vapor raw material 35 is stored in the second container 32. The second container 32 is installed in the first container 31.

The second container 32 is provided by a heater 33 of the first container 31, a temperature sensor (not shown) for measuring the temperature of the second container 32, and a temperature controller (not shown). Temperature is controlled.

In the second container 32, an injection needle serving as a guide attached to the first container 31 is inserted.

The compound vapor generated in the second container 32 reaches the nozzle via a syringe needle pipe and a pipe connected to the pipe.

There is a valve on the way, and the valve can be opened and closed as needed, so that the vapor of the conjugate can be sprayed on the sample surface when needed.

The operation of the valve is performed by the device control computer 7. At the end of the valve is a nozzle through a pipe. Although not shown, the nozzle is adapted to be variable in length.

When compound vapor is sprayed on the sample surface, the nozzle tip is brought close to the sample surface to efficiently spray compound vapor on the sample surface. If it is not necessary to spray compound vapor on the sample surface, keep the nozzle tip away from the sample surface. If the deposition or etching process is performed while spraying the compound vapor onto the sample surface, the position of the nozzle should be the same as that during the processing at the stage of observation to determine the processing region. This is to avoid that the electric field near the sample surface changes depending on the position of the nozzle and the irradiation position of the focused ion beam changes. In general, the heater 33 is shown because the compound becomes a vapor above room temperature. In this case, if the temperature of pipes, valves, nozzles, etc. is low, compound vapor may be deposited at these locations. Therefore, these places are heated by the heater similarly to the first container 31.

In addition, when the material having a high vapor pressure is a compound vapor raw material, the amount of the generated compound vapor may be large at room temperature. In this case, the heater of the first container 31 is a cooling device such as Pelliche, and is controlled to a temperature lower than room temperature. Even if the amount of compound vapor supplied to the sample surface is large or small, desired processing cannot be performed. Therefore, optimization is performed by selecting the temperature and the nozzle opening. Also, the sample stage 26 is moved so that the distance of the sample surface from the nozzle is optimized.

Further, although not shown in FIG. 3, a second valve can be provided. The second valve is located between the nozzle and the valve, and opens and closes between the sample chamber. If the opening of the nozzle is small, there is a possibility that compound vapor may stay between the nozzle and the valve 34.

In this case, since the compound vapor is released into the sample chamber over time, the compound vapor is sprayed onto the sample surface when it is not originally intended, and the effect appears.

Then, after the processing using the compound vapor is completed, the second valve is opened. Since the second valve has a much larger opening than the nozzle, the compound vapor is exhausted to the pipe between the nozzle and the valve 34 by the vacuum pump through the sample chamber. This avoids the previous problem. FIG. 4 shows a more detailed view of the first container 31 and the second container 32.

The second container includes a container body 44, a cap 42 having an opening, and a seal 43 sandwiched between the container body 44 and the cap 42 when the cap 42 is fixed. A needle 41 is attached to the lid 41 of the first container. The pipe of the injection needle 45 is connected to the pipe of the first container body 47 through the lid. Further, the lid 41 of the first container has a mechanism for sandwiching the second container. Thus, the second container can be pulled out of the first container by lifting the lid of the first container. The second container is preferably a transparent container. Thereby, the remaining amount of the compound vapor raw material can be confirmed. Further, it is desirable that the second container is made of a material having high thermal conductivity. This makes it possible to eliminate the temperature gradient in the second container.

FIG. 5 shows an example in which a raw material container for storing a plurality of compound vapor raw materials is connected. Raw material containers are connected to the nozzles via valves 54, respectively. Each raw material container is temperature-controlled at a temperature optimal for the compound vapor raw material.

In this case, the temperature of the nozzle and pipe is also controlled, but the temperature is controlled so that the compound vapor raw material does not precipitate.

In addition, the injection needle may be temperature-controlled in order to reduce the temperature gradient in the second container.

The compound vapor required for the deposition or etching process is sprayed on the sample surface by opening and closing a valve 54 connecting the nozzle and the container for the compound vapor raw material. At this time, the valves 54 connected to the raw material containers are not opened at the same time in order to avoid any reaction from being caused by mixing of a plurality of compound vapors. When the spraying of the first compound vapor is completed, the compound vapor remaining in the pipe is exhausted from the nozzle by the valve 52 connected to the sample chamber so that it does not remain. After sufficiently exhausting the remaining compound vapor, the valve 52 connected to the sample chamber is closed, and the corresponding one of the valves 54 is opened to spray the second compound vapor onto the sample surface.

Also, depending on the type of compound vapor, a mixture of plural compound vapors may be used. Industrial applicability

As described in detail above, according to the present invention, a compound vapor raw material can be packed in a second container in a place where equipment such as a glove box is provided. For example, a focused ion beam equipment manufacturer or a compound vapor raw material manufacturer packs a second container with a compound vapor raw material and supplies it to the focused ion beam equipment user, so that the focused ion beam equipment user can surround the compound vapor raw material. Can be handled without being scattered. As a result, many of the compound vapors that are considered to be necessary for future applications include many dangerous ones, but by applying the present invention, it can be used safely. Become.

Claims

The scope of the claims

1. In a compound vapor spray device attached to a focused ion beam device that irradiates a focused ion beam to a predetermined position of a sample in an atmosphere where compound vapor exists,

A second container for containing the compound in isolation from the atmosphere;

A needle-shaped guide for guiding the compound vapor from the second container to the outside through a part of the second container;

A nozzle communicating with the guide via an on-off valve and spraying the compound vapor to a predetermined position;

And a first container for storing the second container.

2. The compound vapor spray device according to claim 1, wherein

A compound vapor comprising a sample chamber provided between the opening / closing valve and the nozzle, on which the sample is placed, or a second valve connected to one or all of a plurality of sample chambers. Spray device.

3. The compound vapor spray device according to claim 1, wherein

The compound vapor spraying device, wherein the nozzle communicates with a plurality of other compound vapor spraying devices via respective opening / closing valves.

4. The compound vapor spray device according to claim 1, wherein

The said 2nd container is a structure which can see inside, The compound vapor spray apparatus characterized by the above-mentioned.

5. The compound vapor spray device according to claim 1, wherein the second container is made of a material having good heat conductivity.

6. The compound vapor spray device according to claim 1, wherein

The first container has a structure in which the guide portion is attached to a lid, and the guide portion is inserted into the lid of the second container when the second container is stored therein and the lid is closed. Has become

A compound vapor sprayer, wherein the second container is configured to be taken out of the first container by lifting a lid of the first container.

7. The compound vapor spray device according to claim 1, wherein

A compound provided with a temperature control system for controlling the temperature of the first container so as to make the amount of compound vapor generated by the compound contained in the second container a predetermined amount. Steam spray equipment.

8. The compound vapor spray device according to claim 1, wherein

The guide, the nozzle, and the valve communicate with each other via a pipe, and the pipe is temperature-controlled.

9. The compound vapor spray device according to claim 1, wherein the temperature of the nozzle is controlled.

10. The compound vapor spray device according to claim 1, wherein the guide portion is controlled in temperature.

11. The compound vapor spray device according to claim 1, wherein

The second container has a seal, seals the compound, and penetrates the seal with the injection needle-shaped guide.

12. A focused ion beam device comprising at least one compound vapor spray device according to any one of claims 1 to 11.