KR101258817B1 - Plasma gun and plasma processing apparatus having the same - Google Patents

Abstract

Disclosed are a plasma gun capable of increasing the life of an electrode and a plasma processing apparatus comprising the same. Such a plasma gun includes a housing, an electrode and a gas supply. The housing has a cylindrical shape including a first end including an opening and a second end opposite to the first end. The electrode is disposed inside the housing and is supplied with electric power to perform a kitchen discharge through the opening between the anode and the anode. The gas supply unit supplies a plasma generation gas into the housing. On the other hand, the electrode is composed of pieces formed by dividing the disk having a through-hole in the center into two or more pieces, the gas supply portion extends in a direction toward the first end from the second end of the housing In a pipe shape, an end portion of the gas supply part is disposed to penetrate the through hole.

Description

Plasma gun and plasma processing apparatus including the same {PLASMA GUN AND PLASMA PROCESSING APPARATUS HAVING THE SAME}

The present invention relates to a plasma gun and a plasma processing apparatus including the same, and more particularly, to a plasma gun for generating a plasma outside a process chamber and a plasma processing apparatus including the same.

Indium tin oxide (ITO), which is a transparent conductor in many fields such as a large area substrate used in many large display devices such as a liquid crystal display, a plasma display panel, or a solar cell, is used.

The electron beam deposition method and the sputtering method are widely used for such indium tin oxide thin film formation. However, in these methods, there are some problems, and new methods for depositing ITO and the like have been proposed. For example, in the manufacture of solar cells, when the sputtering method is used to form an ITO layer, a problem arises in that the thin film formed under the ITO layer is damaged, thereby lowering the efficiency of the manufactured solar cell.

In order to solve such a problem, the ion plating method has been proposed. This ion plating method has a number of advantages such as not only high film formation rate, high density film quality, large process margin can be realized, but also the plasma beam can be controlled by a magnetic field.

Plasma guns are widely used in such ion plating methods. The plasma gun shoots a plasma onto a target, such as an indium tin oxide tablet, so that the indium tin oxide is ionized and deposited on a substrate to form an ITO thin film.

To this end, the plasma gun has a gas supply unit for supplying a gas for generating plasma and an electrode to which electric power is supplied to perform a discharging between an anode.

When a strong potential is applied to the electrodes of the indium tin oxide tablet and the plasma gun, electrons are discharged from the electrodes of the plasma gun to cause discharge. The plasma generation gas becomes a plasma and is applied to the indium tin oxide tablet to indium tin oxide. It is ionized and deposited on the substrate.

However, since the electrode is heated to a high temperature by the discharge, it is continuously exposed by thermal expansion and ion collision, and reaches a fatigue limit, so that cracks are generated and propagated in the through-holes, and frequent breakage occurs.

7A and 7B are photographs showing that the electrodes used in the conventional plasma gun are broken, and FIG. 8 is a diagram showing the stresses around the through-holes of the conventional electrodes.

As shown in FIGS. 7A and 7B, it can be seen that the electrode is cracked around the through hole. On the other hand, the cause of such a crack is generated by the concentration of stress around the hole as shown in FIG.

By the way, although the electrode is very expensive, it is frequently damaged by heat, and also by stopping the operation of the plasma processing apparatus for replacement, there is a problem that not only increase the maintenance cost but also greatly reduce the productivity.

Accordingly, the problem to be solved by the present invention is to provide a plasma gun that can increase the life.

In addition, another object of the present invention is to provide a plasma processing apparatus including the plasma gun.

Plasma gun according to an exemplary embodiment of the present invention for achieving this problem includes a housing, an electrode and a gas supply. The housing has a cylindrical shape including a first end including an opening and a second end opposite to the first end. The electrode is disposed inside the housing and is supplied with electric power to perform a kitchen discharge through the opening between the anode and the anode. The gas supply unit supplies a plasma generation gas into the housing. On the other hand, the electrode is composed of pieces formed by dividing the disk having a through-hole in the center into two or more pieces, the gas supply portion extends in a direction toward the first end from the second end of the housing In a pipe shape, an end portion of the gas supply part is disposed to penetrate the through hole.

For example, the electrode may be formed in two pieces so that the center angle of the disk is 180 degrees, or formed in three pieces so that the center angle of the disk is 120 degrees, or may be formed in four pieces so that the center angle of the disk is 90 degrees.

For example, the pieces of the electrode can be mounted and fixed to the frame. In this case, the frame may include carbon or carbon composite.

On the other hand, the housing may include a cylindrical body portion, and the opening portion, and a cap portion coupled to the body portion to form the first end.

In this case, for example, the electrode includes lanthanum hexaboride (LaB6), the gas supply part includes tantalum (Ta), the cap part of the housing includes tungsten (W), and the body part molybdenum (Mo) It may include.

The plasma gun may further include an electrode coil disposed to be spaced apart from the first end of the housing, and an electrode magnet disposed between the housing and the electrode coil.

For example, the plasma gun may further include a mount to which the second end of the housing is attached, and the mount may include a refrigerant storage unit.

A plasma processing apparatus according to an exemplary embodiment of the present invention includes a process chamber, a Hearth, a plasma gun, and a power supply. The plasma process is performed in the process chamber. The Haas is disposed inside the process chamber to carry the source tablet. The plasma gun includes a cylindrical housing including a first end including an opening and a second end opposite to the first end, and disposed inside the housing, and supplied with power to an anode. An electrode for conducting a discharge through the opening, and a gas supply for supplying a gas for generating plasma into the housing. The power supply unit applies a potential difference between the source tablet and the electrode supported on the hearth to operate the source tablet as an anode, and operates the electrode as a cathode to discharge. On the other hand, the electrode is composed of pieces formed by dividing the disk having a through-hole in the center into two or more pieces, the gas supply portion extends in a direction toward the first end from the second end of the housing In a pipe shape, an end portion of the gas supply part is disposed to penetrate the through hole.

The plasma processing apparatus may further include a preheating chamber coupled to the top of the process chamber so as to be open to each other, and the process may be performed while transferring the substrate while preheating.

According to the plasma gun according to the present invention, the life of the electrode can be increased by eliminating the stress concentration caused by the change in cross section, and the productivity can be improved by reducing the number of times of process interruption for electrode replacement.

In addition, it is possible to reduce the replacement cost by replacing only the part of the electrode which is damaged at the end of its service life.

1 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment of the present invention.
FIG. 2 is a cutaway perspective view of a plasma gun according to an exemplary embodiment of the present invention applied to the plasma processing apparatus shown in FIG. 1.
3 is a cross-sectional view of a portion of the plasma gun shown in FIG. 2.
4 is a perspective view of an embodiment of the electrode illustrated in FIGS. 1 to 3.
5 is a perspective view according to another embodiment of the electrode shown in FIGS. 1 to 3.
6 is a perspective view of still another embodiment of the electrode illustrated in FIGS. 1 to 3.
7a and 7b are photographs showing that the electrodes used in the conventional plasma gun are broken.
8 is a diagram showing the stress around the through hole of a conventional electrode.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It will be possible. The present invention is not limited to the following embodiments and may be embodied in other forms. The embodiments disclosed herein are provided so that the disclosure may be more complete and that those skilled in the art will be able to convey the spirit and scope of the present invention. In the drawings, the thickness of each device or film (layer) and regions is exaggerated for clarity of the present invention, and each device may have various additional devices not described herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

1 is a schematic diagram of a plasma processing apparatus according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the plasma processing apparatus 100 according to an exemplary embodiment of the present invention includes a process chamber 110, a hearth 120, a plasma gun 130, and a power supply 140. . The plasma processing apparatus 100 may further include a preheat chamber 150. The plasma process is performed in the process chamber 110. The hearth 120 is disposed inside the process chamber 110 to support the source tablet ST. The plasma gun 130 is disposed on the side of the process chamber 110 to generate a plasma and supply the plasma to the process chamber 110. The power supply unit 140 supplies electric power by applying a potential to the source tablet ST supported on the plasma gun 130 and the hearth 120.

The process chamber 110 may be coupled to the preheat chamber 150 so as to be open to each other. In more detail, the process chamber 110 may be opened at an upper portion thereof, and the preheating chamber 150 may be opened at a lower portion thereof, such that the preheating chamber 150 may be fastened to the upper portion of the process chamber 110.

Through this, the substrate S of the preheating chamber 150 may be disposed above the hearth 120 in the process chamber 110. Although not shown, a heating device is formed inside the preheating chamber 150 to preheat the substrate S inside the preheating chamber 150, and a transfer device is formed to form a substrate in the preheating chamber 150. (S) is conveyed along the advancing direction (D).

In addition, the preheating chamber 150 may be connected to the load lock chamber 160 through the gate valve 170. The processed substrate S may be transferred to the load lock chamber 160 through an open gate valve 170.

The hearth 120 is disposed under the process chamber 110 to contain and support the source tablet ST. The source tablet ST includes, for example, the same material as the thin film formed on the substrate S in a cylindrical shape. For example, when the indium tin oxide (ITO) thin film is formed on the substrate S, the source tablet ST includes indium tin oxide. The hearth 120 may include a heating device (not shown) to heat the source tablet ST.

The plasma gun 130 is coupled to the side of the process chamber 110, for example, and generates a plasma and supplies the plasma to the process chamber 110. The plasma gun 130 is shown attached to the outside of the process chamber 110, but may be disposed inside the process chamber 110. In addition, although the plasma processing apparatus 100 is illustrated as including one plasma gun 130, the plasma processing apparatus 100 may include one or more plasma guns 130. On the other hand, the plurality of plasma gun 130 may be arranged in parallel in order to proceed with a plurality of processes in one chamber, alternatively may be arranged in a radial direction along the circumference of the process chamber (110).

The plasma gun 130 may include a housing 131, an electrode 132 disposed in the housing 131, and a gas supply unit for supplying a plasma generation gas such as argon (Ar) to the interior of the housing 131. 133. The plasma gun 130 may further include an electrode magnet 134 and an electrode coil 135. The plasma gun 130 forms the supplied plasma generation gas into a plasma and supplies it to the chamber 110.

The power supply unit 140 applies an electric potential difference between the source tablet ST supported on the Haas 120 and the electrode 132 of the plasma gun 130 to anode the source tablet ST. ) And the electrode 132 is operated by a cathode to discharge. To this end, the power supply 140 may include a power source 141, a first resistor 142, and a second resistor 143 for applying a potential difference between the electrode 132 and the source tablet ST. Can be.

An anode of the power source 141 is electrically connected to the source tablet ST, and the electrode magnet 134 and the electrode coil 135 are respectively through the first resistor 142 and the second resistor 143. The cathode of the power source 141 is electrically connected to the electrode 132 of the plasma gun 130. The cathode of the power source 141 may be electrically connected to the gas supply unit 133 of the plasma gun 130 so that the gas supply unit 133 may be operated as an auxiliary electrode.

First, when a strong electric field is formed between the gas supply unit 133 and the source tablet ST by the power source 141, electrons are emitted from the shortest end of the gas supply unit 133, and the electric field is discharged by the electric field. An auxiliary discharge (glow discharge) that is moved toward the source tablet ST occurs, and then the electrode 132 is heated to emit hot electrons, thereby proceeding to kitchen discharge (arc discharge). Through this discharge, the process gas injected through the gas supply unit 133 is converted into plasma, and the plasma P generated as described above is processed by the converging coil 210 connected to an external power source (not shown). Guided to the inside, and impacts the source tablet (ST) supported on the Haas 120 to vaporize the source tablet (ST) to generate a reactive vapor (RV).

The reactive vapor RV rises to form a film on the upper substrate S.

FIG. 2 is a cutaway perspective view of a plasma gun according to an exemplary embodiment of the present invention applied to the plasma processing apparatus shown in FIG. 1, and FIG. 3 is a cross-sectional view showing a part of the plasma gun shown in FIG. FIG. 6 is a perspective view of one embodiment of the electrode illustrated in FIGS. 1 to 3, respectively.

2 to 6, the plasma gun 130 is configured to supply a plasma generation gas to the housing 131, the electrode 132 disposed in the housing 131, and the inside of the housing 131. It includes a gas supply unit 133. The plasma gun 130 may further include an electrode magnet 134 and an electrode coil 135.

The housing 131 is formed, for example, in a cylindrical shape, the first end A of the housing 131 includes an opening 131c, and the second end B of the housing 131 is a mount 137. Is attached to. For example, as shown in FIG. 3, the housing 131 includes a cylindrical body portion 131a and a cap portion 131b fastened to the body portion 131a to form the first end A. FIG. Can be formed. As such, when the housing 131 is formed to include the body portion 131a and the cap portion 131b, it is convenient to form the electrode 132 in the housing 131 and the electrode 132. It is easy to replace when broken. For example, the cap portion 131b of the housing 131 may include tungsten (W), and the body portion 131a may include molybdenum (Mo).

The electrode 132 is composed of pieces formed by dividing a disk having a through hole h in a central portion into two or more pieces. For example, as shown in FIG. 4, the electrode 132 is formed in two pieces such that the center angle α of the disk is 180 degrees, or as shown in FIG. 5, the center angle α of the disk is 120 degrees. It may be formed in three pieces, or as shown in Figure 6, it can be formed in four pieces so that the center angle (α) of the disk is 90 degrees. Although not shown, the electrode 132 may be divided into four or more pieces 132a. The divided pieces of the electrode 132 include, for example, lanthanum hexaboride (LaB6).

Meanwhile, the divided pieces 132a of the electrode 132 are mounted to the frame 132b. This frame 132b includes an outer rim 1321, a center rim 1322, and a support 1323.

The outer edge 1321 has a circular shape that can be inserted into the cylindrical housing 131. The center edge 1322 has a circular shape like the outer edge 1321, and is disposed concentrically with the outer edge 1321. The support 1323 connects the outer edge 1321 and the center edge 1322. For example, as shown in FIG. 4, the support 1323 is arranged in two so that the center angle α is 180 degrees, or as shown in FIG. Alternatively, as shown in FIG. 6, four discs may be arranged such that the center angle α of the disc is 90 degrees. Although not shown, the support 1323 may have four or more numbers. For convenience of description, the outer edge 1321, the center edge 1322, and the support 1323 are described by giving a separate name, but may be integrally formed.

On the other hand, the frame 132b includes a conductive material that can withstand high temperatures. For example, the frame 132b may include carbon or carbon composite. Therefore, the power applied to the mount 137 is applied to the electrode pieces 132a through the body portion 131a and the frame 132b.

Therefore, stress concentration generated in the through hole h can be alleviated to reduce the occurrence of cracks. In addition, even if any one of the divided pieces 132a of the electrode 132 is broken, the replacement cost can be reduced because only a part of the divided pieces 132a is broken.

The gas supply unit 133 supplies a plasma generation gas into the housing 131. The gas supply unit 133 has a pipe shape extending in a direction from the second end B of the housing 131 toward the first end A, and allows the gas for plasma generation to flow therethrough. One end of the gas supply unit 133 is inserted into the through hole h of the electrode 132 and penetrates the electrode 132, and the other end is attached to the mount 137 to receive power to operate as an auxiliary electrode. can do.

On the other hand, the one end of the gas supply unit 133 may be formed pointed, or may include a number of pointed protrusions. When the end portion of the gas supply part 133 is sharply formed, electrons may be easily emitted during auxiliary discharge. For example, the gas supply unit 133 may include tantalum (Ta).

The mount 137 may include a coolant storage unit 138 and may reduce the thermal expansion of the electrode 132 by lowering the temperature of the plasma gun 130 by flowing the coolant through the flow path 139.

On the other hand, the plasma gun 130 according to an embodiment of the present invention may further include an outer housing 136, an electrode coil 135 and an electrode magnet 134 surrounding the housing, the outer housing ( 136 is formed in a cylindrical shape surrounding the housing 131, the electrode magnet 134 and the electrode coil 135 is sequentially fastened to the outer housing 136.

According to the plasma gun according to the present invention, the life of the electrode can be increased by eliminating the stress concentration caused by the change in cross section, and the productivity can be improved by reducing the number of times of process interruption for electrode replacement.

In addition, it is possible to reduce the replacement cost by replacing only the part of the electrode which is damaged at the end of its service life.

While the present invention has been described in connection with what is presently considered to be practical and exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: plasma processing apparatus 110: process chamber
120: Hearth 130: plasma gun
131: housing 131a: body portion
131b: cap 132: electrode
132a: electrode pieces 132b: frame
133: gas supply unit 134: electrode magnet
135: electrode coil 136: outer housing
137: mount 138: refrigerant storage unit
139: Euro 140: power supply
141: power supply 142: first resistor
143: second resistance 150: preheating chamber
160: load lock chamber 170: gate valve
210: converging coil 601: fixing screw
1321: outer border 1322: center border
1323: support 138: refrigerant storage unit
P: plasma S: substrate
ST: Source Tablet RV: Reactive Vapor

Claims (13)

A cylindrical housing including a first end including an opening and a second end opposite the first end;
An electrode disposed inside the housing and supplied with electric power to perform an electric discharge through the opening between the anode and the anode; And
A gas supply unit for supplying a gas for plasma generation inside the housing;
The electrode is composed of pieces formed by dividing the disk having a through-hole in the center into two or more pieces,
And the gas supply part has a pipe shape extending in a direction from the second end of the housing toward the first end part, wherein the end of the gas supply part passes through the through hole. The method according to claim 1,
The electrode is formed in two pieces, the disk is divided into two,
The disk is formed into three pieces, or
Plasma gun, characterized in that the disk is formed of four pieces divided into quarters. The method according to claim 1,
And the pieces of electrode are mounted to a frame. 4. The plasma gun of claim 3, wherein the frame comprises carbon or carbon composite. The method according to claim 1,
The housing includes:
Cylindrical body portion; And
And a cap portion including the opening portion and a cap portion coupled to the body portion to constitute the first end portion. 6. The method of claim 5,
The electrode comprises lanthanum hexaboride (LaB6),
The gas supply part includes tantalum (Ta),
And the cap portion of the housing comprises tungsten (W) and the body portion comprises molybdenum (Mo). The method according to claim 1,
An electrode coil disposed to be spaced apart from the first end of the housing; And
And a electrode magnet disposed between the housing and the electrode coil. The method according to claim 1,
Further comprising a mount to which the second end of the housing is attached,
And the mount includes a refrigerant reservoir. A process chamber in which the plasma process is performed;
A hearth disposed inside the process chamber to support a source tablet;
A cylindrical housing including a first end including an opening and a second end opposite to the first end, and disposed within the housing and supplied with power through the opening between the anode and the anode. A plasma gun including an electrode for conducting discharging and a gas supply unit for supplying a gas for generating plasma into the housing; And
A power supply for applying a potential difference between the source tablet and the electrode supported on the hearth to operate the source tablet as an anode, and to operate the electrode as a cathode to discharge;
The electrode is composed of pieces formed by dividing the disk having a through-hole in the center into two or more pieces,
And the gas supply part has a pipe shape extending in a direction from the second end of the housing toward the first end part, wherein the end of the gas supply part passes through the through hole. 10. The method of claim 9,
The electrode is formed in two pieces, the disk is divided into two,
The disk is formed into three pieces, or
Plasma processing apparatus, characterized in that the disk is formed of four pieces divided into quarters. 10. The method of claim 9,
And the pieces of the electrode are mounted on a frame made of carbon or a carbon composite. 10. The method of claim 9,
The housing includes:
Cylindrical body portion; And
A cap part including the opening part and coupled to the body part to constitute the first end part,
The electrode includes lanthanum hexaboride (LaB6), the gas supply part includes tantalum (Ta), the cap part of the housing includes tungsten (W), and the body part includes molybdenum (Mo). Plasma processing apparatus, characterized in that. 10. The method of claim 9,
And further comprising a preheating chamber coupled to the top of the process chamber to open towards the bottom of the process chamber,
Plasma processing apparatus characterized in that the process proceeds while performing the preheating and transfer of the substrate at the same time.

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