US20070068624A1

US20070068624A1 - Apparatus to treat a substrate and method thereof

Info

Publication number: US20070068624A1
Application number: US11/532,166
Authority: US
Inventors: Yun-kwang Jeon; Yung-hee Lee; Jin-Seok Lee
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2005-09-28
Filing date: 2006-09-15
Publication date: 2007-03-29
Also published as: JP2007096299A; KR100653073B1

Abstract

An apparatus to treat a substrate including a vacuum chamber having a plasma space where plasma is generated and a treating space where a substrate is treated, an extract electrode disposed between the plasma space and the treating space, a power supply to provide power to the extract electrode, and a controller to control the power supply so that a cation beam and a negative charge beam are alternately extracted from a plasma in the plasma space to the treating space.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Korean Patent Application No. 2005-0090693, filed on Sep. 28, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present general inventive concept relates to an apparatus to treat a substrate and a method of treating the substrate, and more particularly, to an apparatus to treat a substrate and a method of treating a substrate which uses a cation beam and a negatively charged beam alternately extracted from a plasma.
2. Description of the Related Art
A semiconductor wafer or a substrate for display devices (hereinafter, referred as a substrate) is manufactured by performing processes of repeatedly depositing and etching thin films on the substrate. Generally, a process of etching an insulating layer can be performed with an ion beam extracted from a plasma and having a directivity. The process using the plasma has advantages of an anisotropic etching characteristic and a high etching efficiency.
In the process of etching the insulating layer using the ion beam, the ion beam having the directivity is formed by a potential difference of an electrical property of the ion. Thus, the ion beam is incident to the insulating layer and etches the insulating layer while maintaining its directivity.
However, a current path is not formed in the insulating layer, so that electric charges of the incident ion beam become charged up in the insulating layer. Then, the electric charges destroy the insulation and damage the substrate, causing a defective etching known as undercut.
To solve this problem, the ion beam is converted into a neutral beam, or electric charges with opposite polarity to the electric charges accumulated in the substrate are supplied for charge compensation.
These conventional solutions to such charge build up are described as follows.
One conventional method of converting an ion beam into a neutral beam is extracting an electron from an electron gun or an electron extractor to be incident to a course of a cation. Accordingly, the electron collides with the cation to cause an energy transfer, and the cation is neutralized. When the cation collides with the electron, which has a comparatively small mass, the cation does not change its course.
Another conventional method of converting an ion beam into a neutral beam is that an ion beam passes through a neutralizer. The ion beam with directivity collides with a reflector in the neutralizer at a small incident angle and is reflected at the same angle. The charge exchange is generated during the collision, thereby neutralizing the ion beam. Further, the angle of reflection is constant, so that the ion beam has directivity.
The conventional method of providing an electric charge with an opposite polarity includes providing an electron directly to the substrate where a cation beam is incident using an electron supply such as an electron gun. In this conventional method, a positive charge accumulated by the cation beam is counterbalanced by a negative charge from the electron.
However, these conventional methods have the following problems.
First, in the conventional method of neutralizing the cation beam using the electron, an electron supply is necessary in addition to an ion beam extractor. Further, the collision is generated from the circumference of the cation beam to the center thereof, so that the cation beam may not properly be neutralized in the center.
Second, in the conventional method of neutralizing the ion beam using a reflector, an energy of a neutral particle decreases by the collision. Further, the reflector may be heat-transformed, deposited with polymer, arched, etc., due to the collision, and the ion beam may easily lose directivity according to an intensity of illumination of the reflector.
Third, in the conventional method of providing an electric charge with the opposite polarity, a device that directs the electron gun toward the substrate or supplies the electron with directivity using a magnetic field may become complicated.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present general inventive concept to provide an apparatus to treat a substrate having a simple a structure and to destroy less insulation in an insulating layer to be treated.
Another aspect of the present general inventive concept is to provide a method of treating a substrate using an apparatus to treat a substrate having a simple a structure and to destroy less insulation in an insulating layer to be treated.
Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.
The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing an apparatus to treat a substrate comprising a vacuum chamber including a plasma space where a plasma is generated and a treating space where a substrate is treated, an extract electrode disposed between the plasma space and the treating space, a power supply to provide power to the extract electrode, and a controller to control the power supply so that a cation beam and a negative charge beam are alternately extracted from the plasma in the plasma space and provided to the treating space.
The negative charge beam may comprise at least one of an electron beam and an anion beam.
The extract electrode may comprise a plurality of grids.
The plurality of the grids may be arranged parallel with each other.
The controller may control the power supply to supply different voltages to the plurality of the grids respectively.
The controller may control the power supply to supply a ground voltage to the grid which contacts the treating space.
The apparatus to treat the substrate may further comprise ammeters to measure current values in each of the grids and to transmit the current values to the controller.
The controller may control the power supply so that the cation beam is extracted for a same time as the negative charge beam.
The controller may control the power supply so that the cation beam provided to the treating space has the same amount of an electric charge as the negative charge beam provided to the treating space.
The apparatus to treat the substrate may further comprise an ammeter to measure a current value in the substrate to be treated and to transmit the current value to the controller.
The apparatus to treat the substrate further comprises a table disposed under the treating space and on which the substrate to be treated is seated.
The apparatus to treat the substrate may further comprise a coil disposed outside the vacuum chamber to generate an induced-coupled plasma to the plasma space and a plasma forming power supply to provide power to the coil.
The apparatus to treat the substrate may further comprise an impedance matching unit disposed between the coil and the power supply.
The apparatus to treat the substrate may further comprise the reactant gas supply to supply a reactant gas to the plasma space.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a method of treating a substrate comprising placing a substrate including an exposed insulating layer to be treated on a table inside a vacuum chamber, generating a plasma in a plasma space adjacent to the table, and extracting a cation beam and a negative charge beam alternately from the plasma to be provided to the substrate to be treated.
In the extracting of the negative charge beam, the negative charge beam may comprise at least one of an electron beam and an anion beam.
In the extracting of the cation beam, the cation beam may be extracted for substantially a same period of time as the negative charge beam.
In the extracting of the cation beam, the cation beam may substantially have the same amount of an electric charge as the negative charge beam which is provided to the substrate to be treated.
The extracting of the cation beam and negative charge beam is performed by disposing an extract electrode between the substrate to be treated and the plasma space.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing an extract electrode apparatus to neutralize a cation beam and a negative charge beam usable in an apparatus to treat a substrate using a plasma, comprising one or more grids sequentially arranged between the substrate and the plasma in the apparatus to treat a substrate and a controller to control voltages supplied to each of the one or more grids to extract the cation beam and the negative charge beam alternately from the plasma and provide the extracted cation beam and the negative charge beam alternately into a space between the extract electrode and the substrate.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a plasma etching apparatus to treat a substrate, comprising a chamber to supply a plasma, an extract electrode provided in the chamber, including a first grid layer, a second grid layer, and a third grid layer each provided in a same shape and in parallel and vertically arranged and having through holes defined therein, and a controller to control voltages provided to each of the first, second, and third grids to prevent an accumulation of charges on a substrate within the chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a sectional view illustrating an apparatus to treat a substrate according to an exemplary embodiment of the present general inventive concept;
FIG. 2 is a perspective view illustrating a grid in the apparatus of FIG. 1 to treat the substrate according to an exemplary embodiment of the present general inventive concept;
FIG. 3 is a graph illustrating a voltage which is applied to the grid in the apparatus of FIG. 1;
FIG. 4 is a graph illustrating potentials of a cation beam and an anion beam in the apparatus of FIG. 1; and
FIG. 5 is a flow chart illustrating a method of treating a substrate according to an exemplary embodiment of the present general inventive concept.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.
FIG. 1 is a sectional view illustrating an apparatus 1 to treat a substrate 100 according to an exemplary embodiment of the present general inventive concept.
The apparatus 1 to treat the substrate 100 comprises a vacuum chamber 10 having a treating space 31 and a plasma space 32 formed therein, a table 21 on which the substrate 100 to be treated is placed, an extract electrode 41 to extract a cation beam and a negative charge beam from plasma, and a coil 81 and a plasma forming power supply 82 which form the plasma. The extract electrode 41 is connected to a power supply 51, and electric power supplied to the extract electrode 41 by the power supply 51 is controlled by a controller 71.
The vacuum chamber 10 comprises the extract electrode 41, the treating space 31 where the substrate 100 is treated, and the plasma space 32 where the plasma is formed and keeps the spaces 31 and 32 in a vacuum state and at a constant temperature. A reactant gas supply 11 is provided in an upper lateral side of the vacuum chamber 10, and a reactant gas to form the plasma flows therefrom. The reactant gas may comprise CFx, Ar, O2, SF6, etc.
An exhaust hole 12 is formed in a lower part of the vacuum chamber 10 to discharge a by-product or the like generated during a reaction within the vacuum chamber 10. The vacuum chamber 10 may further comprise a vacuum pump (not illustrated) connected to the exhaust hole 12.
The table 21 where the substrate 100 to be treated is placed is disposed in the lower part of the vacuum chamber 10. A portion of an insulating layer of the substrate 100 is exposed to be etched and another portion thereof is covered with a photoresist layer so as not to be etched.
The treating space 31 is disposed above the table 21 and the plasma space 32 is formed in an upper part of the treating space 31 across the extract electrode 41.
The extract electrode 41 is disposed between the treating space 31 and the plasma space 32. The extract electrode 41 comprises three grids 41 a, 41 b and 41 c. Three grids 41 a, 41 b and 41 c are disposed parallel with each other. As illustrated in FIG. 2, each of the grids 41 a, 41 b and 41 c has a rectangular plate having a plurality of through holes 42 provided therein, which are disposed in rows. A shape of the grids 41 a, 41 b and 41 c and an arrangement of the through holes 42 may be modified as necessary.
The extract electrode 41 is supplied with an electric power from the power supply 51 and alternately transmits the cation beam and the negative charge beam to the treating space 31. The grids 41 a, 41 b and 41 c each are connected to independent electric power units 51 a, 51 b and 51 c to be independently supplied with the electric power.
Ammeters 61 a, 61 b and 61 c each are connected between the grids 41 a, 41 b and 41 c and the independent electric power units 51 a, 51 b and 51 c to measure current values which substantially flow in the grids 41 a, 41 b and 41 c. Meanwhile, the substrate 100 is connected to an ammeter 61 d as well to measure a charge accumulation in the substrate 100.
The controller 71 controls the electric power which the power supply 51 provides to the extract electrode 41. The controller 71 alternately extracts a cation beam and a negative charge beam from plasma in the plasma space 32 to control the electric power, thereby transmitting the cation beam and negative charge beam to the treating space 31. The controller 71 controls the power supply 51 by feedback of the current values measured by each of the ammeters 61 a, 61 b, 61 c and 61 d so as not to generate a charge accumulation in the substrate 100.
The coil 81 is disposed outside the vacuum chamber 10 to correspond to the plasma space 32 and is connected to the plasma forming power supply 82. The plasma forming power supply 82 supplies high-frequency electric power to the coil 81, and a frequency of the high-frequency electric power may be in a range of several kHz to hundreds of MHz. Induced-coupled plasma is formed in the plasma space 32 as the plasma forming power supply 82 supplies the electric power. An impedance matching unit 83 is provided between the coil 81 and the plasma forming power supply 82.
The apparatus 1 to treat the substrate extracts the cation beam and the negative charge beam alternately from the plasma in the plasma space 32. The extract electrode 41 selectively extracts the cation beam and/or the negative charge beam using a relation between energies of the beams and a potential of the extract electrode 41. This method is disclosed in page 61 to 64 of “THE PHYSICS AND TECHNOLOGY OF ION SOURCES”, Second edition, by Ian G. Brown.
Hereinafter, a method of extracting a cation beam and a negative charge beam from plasma, according to an embodiment of the present general inventive concept, will be described with reference to FIGS. 3 and 4.
The negative charge beam according to the present embodiment of FIGS. 3 and 4 is an anion beam and/or an electron beam which can neutralize the cation beam. Hereinbelow, a negative charge beam will be described with an anion beam as an example.
FIG. 3 is a graph illustrating a voltage applied to each of the grids 41 a, 41 b, and 41 c in the apparatus of FIG. 1, and FIG. 4 is a graph illustrating potentials of the cation beam and the anion beam in the apparatus of FIG. 1 according to the embodiment of FIGS. 3 and 4.
FIG. 3 illustrates that the voltages provided to each of the grids 41 a, 41 b and 41 c have different patterns. The voltages provided to the first grid 41 a and the second grid 41 b each form a rectangular wave which vary at a constant period and alternate with respect to each other. The third grid 41 c is provided with a ground voltage regardless of time.
In the present exemplary embodiment, when the first grid 41 a has a low potential and the second grid 41 b has a high potential, the anion beam is extracted. In contrast, when the first grid 41 a has a high potential and the second grid 41 b has a low potential, the cation beam is extracted. The anion beam is extracted within the same time period as the cation beam. Frequencies of the first grid 41 a and the second grid 41 b may be in a range of 1 Hz and hundreds of kHz.
The controller 71 controls the power supply 51 so that the electric powers provided to each of the grids 41 a, 41 b and 41 c have the patterns illustrated in FIG. 3, respectively. In this method, the controller 71 may modify the patterns of the electric powers based on the current values measured by the ammeters 61 a, 61 b, 61 c and 61 d.
In the present embodiment, the voltages provided to the first grid 41 a and the second grid 41 b may form a sine wave, a triangular wave, etc., in addition to the rectangular wave.
FIG. 4 illustrates potentials of the cation beam and the anion beam with respect to a vertical direction Z in the vacuum chamber 10.
The potential of the cation beam rapidly decreases between the first grid 41 a and the second grid 41 b, and slowly increases between the second grid 41 b and the third grid 41 c. The potential of the anion beam rapidly increases between the first grid 41 a and the second grid 41 b, and slowly decreases between the second grid 41 b and the third grid 41 c.
The apparatus 1 to treat the substrate according to the exemplary embodiment of FIG. 1 may be modified. For example, in another embodiment, the number of grids may be one or more.
Hereinafter, a method of treating a substrate 100 using the apparatus of FIG. 1 to treat the substrate 100 according to an embodiment of the present general inventive concept will be described with reference to FIG. 5. FIG. 5 is a flow chart illustrating a method of treating a substrate according to an exemplary embodiment of the present general inventive concept.
First, the substrate 100 to be treated is placed on the table 21 (Operation S100). One portion of the insulating layer of the substrate 100 is exposed to be etched, and another portion of the insulating layer not to be etched is covered with a photoresist layer. The insulating layer comprises silicon nitride or silicon oxide, and wiring made of metal may be disposed thereunder. The substrate 100 may be a semiconductor wafer or a substrate usable in display devices, such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device and an organic light emitting diode (OLED) device.
After the substrate 100 is placed on the table 21, a temperature and a pressure inside the vacuum chamber 10 are adjusted.
Then, a high-frequency electric power is applied to the coil 81 through the plasma forming power supply 82 while a reactant gas is supplied into the vacuum chamber 10 through the reactant gas supply 11. Accordingly, the plasma is formed from the reactant gas by an inductive coupling in the plasma space 32 (Operation S200). The plasma comprises the cation beam and either the anion or the electron beam as the negative charge beam.
When the plasma is formed, the cation beam and the negative charge beam are alternately extracted by adjusting the voltages applied to each of the grids 41 a, 41 b and 41 c of the first extract electrode 41 to be transmitted to the treating space 31 (Operation S300). The negative charge beam may be the anion beam and/or the electron beam and has substantially the same amount of an electric charge as the cation beam.
The cation beam and the negative charge beam provided to the treating space 31 are incident to the substrate 100 to etch the exposed insulating layer (Operation S400). In this process, the cation beam and the negative charge beam are neutralized, thereby not accumulating electric charges in the insulating layer. Thus, a destruction or detraction of a quality of the insulation layer is reduced.
As described above, an apparatus to treat a substrate according to an embodiment of the present general inventive concept, which can use a plurality of plasma spaces, and extract electrodes to prevent charge accumulation in an insulating layer without a neutralizer or the like, is provided.
Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.

Claims

1. An apparatus to treat a substrate, comprising:

a vacuum chamber including a plasma space where a plasma is generated and a treating space where a substrate is treated;

an extract electrode disposed between the plasma space and the treating space;

a power supply to provide power to the extract electrode; and

a controller to control the power supply so that a cation beam and a negative charge beam are alternately extracted from the plasma in the plasma space and provided to the treating space.

2. The apparatus to treat the substrate according to claim 1, wherein the negative charge beam comprises at least one of an electron beam and an anion beam.

3. The apparatus to treat the substrate according to claim 1, wherein the extract electrode comprises a plurality of grids.

4. The apparatus to treat the substrate according to claim 3, wherein the plurality of the grids are arranged parallel with each other.

5. The apparatus to treat the substrate according to claim 3, wherein the controller controls the power supply to supply different voltages to the plurality of the grids respectively.

6. The apparatus to treat the substrate according to claim 3, wherein the controller controls the power supply to supply a ground voltage to the grid which contacts the treating space.

7. The apparatus to treat the substrate according to claim 3, further comprising ammeters to measure current values in each of the grids and to transmit the current values to the controller.

8. The apparatus to treat the substrate according to claim 1, wherein the controller controls the power supply so that the cation beam is extracted for a same period of time as the negative charge beam.

9. The apparatus to treat the substrate according to claim 1, wherein the controller controls the power supply so that the cation beam provided to the treating space has the same amount of an electric charge as the negative charge beam provided to the treating space.

10. The apparatus to treat the substrate according to claim 1, further comprising an ammeter to measure a current value in the substrate to be treated and to transmit the current value to the controller.

11. The apparatus to treat the substrate according to claim 1, further comprising a table disposed under the treating space and on which the substrate to be treated is seated.

12. The apparatus to treat the substrate according to claim 1, further comprising:

a coil disposed outside the vacuum chamber to generate an induced-coupled plasma to the plasma space; and

a plasma forming power supply to provide power to the coil.

13. The apparatus to treat the substrate according to claim 12, further comprising an impedance matching unit disposed between the coil and the power supply.

14. The apparatus to treat the substrate according to claim 1, further comprising a reactant gas supply to supply a reactant gas to the plasma space.

15. An extract electrode apparatus to neutralize a cation beam and a negative charge beam usable in an apparatus to treat a substrate using a plasma, comprising:

one or more grids sequentially arranged between the substrate and the plasma in the apparatus to treat a substrate; and

a controller to control voltages supplied to each of the one or more grids to extract the cation beam and the negative charge beam alternately from the plasma and provide the extracted cation beam and the negative charge beam alternately into a space between the extract electrode and the substrate.

16. The extract electrode apparatus of claim 15, wherein the controller comprises:

one or more ammeters to measure currents in each respective grid and to provide the measured results to the controller such that the controller controls the voltages to each of the grids to prevent charge accumulation in the substrate.

17. The extract electrode apparatus of claim 16, wherein the controller further comprises:

a substrate ammeter to measure charge accumulation in the substrate and to provide the measured results to the controller such that the controller controls the voltages to each of the grids to prevent charge accumulation in the substrate.

18. The extract electrode apparatus of claim 16, wherein the controller comprises:

one or more independent power units to provide a respective one of the voltages to each respective grid based on the currents measured by the respective one of the ammeters.

19. The extract electrode apparatus of claim 15, wherein each of the grids has through holes defined therein

20. The extract electrode apparatus of claim 15, wherein the one or more grids comprise:

a first grid furthest from the substrate;

a second grid provided between the first grid and the substrate; and

a third grid provided between the second grid and the substrate.

21. A plasma etching apparatus to treat a substrate, comprising:

a chamber to supply a plasma;

an extract electrode provided in the chamber, including a first grid layer, a second grid layer, and a third grid layer each provided in a same shape and in parallel and vertically arranged and having through holes defined therein; and

a controller to control voltages provided to each of the first, second, and third grids to prevent an accumulation of charges on a substrate within the chamber.

22. The apparatus of claim 21, further comprising a table provided in the chamber to support the substrate to be treated.

23. The apparatus of claim 21, wherein the controller comprises a measuring device to measure a charge on the substrate and controls the voltage based on the measured charge.

24. The apparatus of claim 21, wherein the controller controls the extract electrode to alternately extract a cation beam and a negative charge beam.

25. A method of treating a substrate comprising:

placing a substrate including an exposed insulating layer to be treated on a table inside a vacuum chamber;

generating a plasma in a plasma space adjacent to the table; and

extracting a cation beam and a negative charge beam alternately from the plasma to be provided to the substrate to be treated.

26. The method of treating the substrate according to claim 25, wherein in the extracting of the negative charge beam, the negative charge beam comprises at least one of an electron beam and an anion beam.

27. The method of treating the substrate according to claim 25, wherein in the extracting of the cation, the cation beam is extracted for substantially a same time as the negative charge beam.

28. The method of treating the substrate according to claim 25, wherein in the extracting of the cation, the cation beam has substantially the same amount of an electric charge as the negative charge beam which is provided to the substrate to be treated.

29. The method of treating the substrate according to claim 25, wherein the extracting of the cation beam and negative charged beam, is performed by disposing an extract electrode between the substrate to be treated and the plasma space.