KR100683255B1 - Plasma processing apparatus and exhausting device - Google Patents

Abstract

A plasma processing apparatus and an exhausting apparatus are provided to obtain a smooth gas flow by keeping uniformly the flow of a process gas and retaining constantly the pressure of the process gas using a buffer chamber and an exhaust port. A plasma processing apparatus comprises a vacuum chamber(110), an upper electrode part(112) at an inner upper portion of the vacuum chamber, a lower electrode part, an exhaust port and a buffer chamber. The lower electrode part(116) is installed opposite to the upper electrode part. A plurality of additional lines are connected to a lower portion of the lower electrode part. The exhaust port(156) is formed at one lower side of the vacuum chamber. The buffer chamber(154) includes an opening portion capable of passing the plurality of additional lines.

Description

Plasma Processing Apparatus and Exhausting Device

1 is a cross-sectional view of a conventional plasma processing apparatus.

2 is a cross-sectional view schematically showing a buffer chamber and a plasma processing apparatus equipped with the same according to the present invention.

3A to 3C are plan and cross-sectional views of the buffer chamber according to the present invention.

4A to 4E are plan views schematically illustrating various types of buffer chambers.

5 is a cross-sectional view schematically showing a buffer chamber and a plasma processing apparatus equipped with the buffer chamber according to another embodiment of the present invention.

6A and 6B are a plan view and a cross-sectional view of the lower ground plate.

              <Description of the code | symbol about the principal part of drawings>

10, 110: vacuum chamber 12, 112: upper electrode portion

14, 114: substrate 16, 116: lower electrode plate

18, 118: electrostatic chuck 20, 120: second high frequency power supply

22, 138: DC high voltage power supply 24, 124: porous exhaust plate

26, 156: exhaust port 28, 128: second matcher

130: gas supply source 132: insulating support member

134: focus ring 136: line

142: gas discharge hole 144: upper electrode plate

146: shield ring 148: first matching device

150: first high frequency power supply 152: lower electrode portion

154: buffer chamber 158, 258: inner support tube

160: outer opening 162, 262: outer support tube

164, 264: support 166, 266: inner opening

168: screw groove 170: lower ground plate

TECHNICAL FIELD The present invention relates to a semiconductor processing apparatus, and more particularly, to a gas flow when a predetermined gas for processing a substrate in a vacuum chamber is discharged by an exhaust port connected to a buffer chamber via the porous exhaust plate in the plasma region portion above the porous exhaust plate. The present invention relates to a plasma processing apparatus capable of generating a uniform plasma by keeping a constant.

As the semiconductor and display industries develop, processing of substrates such as wafers and glass is also progressing toward minimizing and integrating desired patterns in a limited area. Accordingly, plasma processing technology is widely used when growing or etching a thin film of a substrate. Plasma treatment is widely used in processing processes of semiconductors, display substrates, etc. due to the advantages of controlling the process at high density. The plasma processing apparatus includes a single type or batch type apparatus. In the single type plasma processing apparatus, electrodes are disposed up and down in a vacuum chamber to generate a plasma by applying high frequency power between both electrodes.

1 shows a general sheet type semiconductor plasma processing apparatus. Referring to the drawings, the plasma processing apparatus includes a substrate support member disposed in the vacuum chamber 10 opposite the upper electrode 12 and the upper electrode 12, and on which the semiconductor substrate 14, which is an object to be processed, is mounted. The substrate support member includes a lower electrode 16 and an electrostatic chuck 18 to which a first high frequency power is applied. The upper electrode 12 and the lower electrode 16 are spaced apart from each other by a predetermined interval to face each other, and the high frequency power matched from the outside is applied, and the vacuum chamber is applied by the high frequency power applied between the upper and lower electrodes 12 and 16. The gas in 10 is ionized and generates a high density plasma in the space between the upper and lower electrodes 12, 16. Here, an electrostatic chuck 18 on which the substrate 14 is mounted is provided on the lower electrode 16, and the lower part of the lower electrode 16 is made of an insulator. In order to electrostatically adsorb the substrate 14, a DC voltage is applied to the electrostatic chuck 18 through a constant DC high voltage power supply 22, and the substrate 14 is fixed to the electrostatic chuck 18. High-frequency power is applied between the upper and lower electrodes 12 and 16 to generate plasma P, and the plasma P is subjected to a predetermined plasma treatment on the substrate 14. In addition, a porous exhaust plate 24 is provided on the lower surface side of the lower electrode 16. The porous exhaust plate 24 separates the plasma processing space and the exhaust space, and the plasma processing space gas is exhausted by the exhaust port 26 through the porous exhaust plate 24. In such a semiconductor plasma processing apparatus, it is very important to stably generate and maintain a high density uniform plasma in order to increase the uniformity and yield of the process. The use of the high frequency power supply 20 makes it possible to generate a high density plasma, but how uniformly the plasma is generated and maintained is not just a matter of power supply. Of course, the electrical problem of constantly applying the high frequency power source 20 through the matching unit 28 without loss or variation is important, but the flow until the injected gas is exhausted in a situation where the inside of the processing chamber is maintained at a constant pressure is stable. You can't ignore this problem. However, the conventional exhaust device 26 is connected to the side wall in the vacuum chamber 10, resulting in significant non-uniformity in the exhaust gas flow.

Therefore, in order to solve the above problem, it is necessary to adjust the exhaust system of the vacuum chamber to control the flow of gas inside the entire vacuum chamber. However, a path through which additional lines necessary for each matter, such as a heat transfer gas supply line, a direct current high voltage power supply, a high frequency power supply, a cooling line, and a temperature sensor line, must be formed in the lower electrode portion, and a process gas exhaust line must be formed at the same time. Therefore, adjusting the structure of the exhaust system is not a simple matter. In order to form the path of the additional lines, a small area is required, and at the same time, in order to stably maintain the flow of the gas exhausted by the high vacuum pump, a structure for simultaneously forming the path of the exhaust opening and the additional line is provided. Branches are important to form an exhaust system. In addition, the exhaust system should be configured to have a minimum obstacle so that the flow of exhaust gas can be maintained smoothly. If the flow of the exhaust gas is biased in one direction or if the exhaust gas is not smoothly exhausted, a difference in the internal pressure of the processing chamber occurs, thereby lowering the uniformity of the plasma.

Accordingly, the present invention was derived to solve the above problems, and reconfigures the shape of the exhaust pipe (hereinafter referred to as "buffer chamber") and the position of the exhaust port through which the process gas inside the vacuum chamber of the plasma apparatus is exhausted. It is an object of the present invention to provide a buffer chamber for maintaining a constant flow and a plasma processing apparatus using the same.

In order to achieve the above object, the plasma processing apparatus of the present invention includes a vacuum chamber, an upper electrode portion located above the vacuum chamber, a lower electrode portion positioned opposite to the upper electrode portion, and having a plurality of additional lines connected to the lower portion; And a buffer chamber positioned at a lower surface of the vacuum chamber and having an exhaust port formed at one side thereof, and having an opening formed therein so that the plurality of additional lines can pass therethrough.
The opening is formed in the center of the inner support tube, the exhaust port is characterized in that installed on the outer peripheral surface of the outer support tube. The opening is formed in the center of the inner support tube, the exhaust port is characterized in that installed on the outer peripheral surface of the outer support tube. The support is characterized in that connecting the upper portion of the inner support tube outer peripheral surface and the outer support tube inner peripheral surface. The support is characterized in that it further comprises a through hole formed through the top and bottom. An O-ring is provided between the buffer chamber and the vacuum chamber. The material of the buffer chamber is characterized in that the stainless steel or aluminum. The exhaust port is characterized in that a plurality is formed on the side of the buffer chamber.
A lower ground plate is further provided between the vacuum chamber and the buffer chamber. The lower ground plate may include an inner support having an opening through the center, an outer support formed at a predetermined distance from an outer circumferential surface of the inner support, and a support connecting the inner circumferential surface of the inner and outer support portions to each other. .
The support portion is characterized in that a plurality is formed. The support portion is characterized in that it covers the upper portion of the outer support. The support portion is characterized in that it further comprises a through hole formed through the top and bottom. The support may cover the upper portion of the outer opening in a plate shape and the support is characterized in that the upper and lower through-holes of a predetermined shape is formed. O-rings are provided between the vacuum chamber, the lower ground plate, and the buffer chamber, respectively. The electrical conductivity of the lower ground plane is higher than that of the buffer chamber.

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2 is a cross-sectional view schematically showing a buffer chamber and a plasma processing apparatus equipped with the same according to the present invention.

Referring to FIG. 2, the plasma processing apparatus of the present invention includes an upper electrode 112 and a lower electrode part in which the substrate 114 which is an object to be processed is mounted in the vacuum chamber 110. 152).

The gas supply 130 and the second high frequency power supply 120 for generating plasma are connected to the upper electrode part 112. The lower electrode part 152 includes a lower electrode plate 116, an electrostatic chuck 118, an insulating support member 132, a focus ring 134, and the like. 136 and additional lines such as a DC high-voltage power supply 138 for electrostatically adsorbing the workpiece 114 to the electrostatic chuck 118 are connected. In addition, the upper sidewall of the vacuum chamber 110 is provided with a substrate loading / unloading outlet and a gate valve G. The substrate 114 is loaded and unloaded with the gate valve G open.

The second high frequency power supply 120 is connected to the upper electrode portion 112 via the second matching unit 128, and a high voltage of 50 to 150 MHz is applied thereto, thereby forming a high density plasma. In addition, the upper electrode part 112 includes an empty space therein, and includes an upper electrode plate 144 formed below and a shield ring 146 surrounding the upper electrode plate 144 and forming sidewalls of the upper electrode part. do. The upper electrode plate 144 is provided with a plurality of gas discharge holes 142 for discharging the plasma processing gas. Therefore, the processing gas flows into the inner space of the upper electrode portion 112 from the gas source 130 and then passes through the discharge hole 142 to form a space between the upper electrode portion 112 and the lower electrode portion 152. Supplied to the processing space.

The edge of the disk-shaped upper electrode plate 144 made of aluminum or the like is fixed to the shield ring 146. The shield ring 146 exposes the lower surface of the upper electrode plate 144 and is formed to cover other portions. The shield ring 146 serves to prevent abnormal discharge.

A first high frequency power supply 150 is connected to the lower electrode portion 152 facing the upper electrode portion 112 and spaced apart from each other by a first matching unit 148. The first high frequency power supply 150 is applied with high frequency power of 1 to 4 MHz. An insulating support member 132 is provided at the bottom of the lower electrode portion 152. At this time, the lower electrode unit 152 may be grounded without a separate power.

Cooling means and heating means for adjusting the substrate 114 to a predetermined temperature may be provided in the lower electrode plate 116 or the insulating support member 132. In addition, an upper surface of the lower electrode plate 116 is provided with an electrostatic chuck 118 that is a holding means for holding a substrate 114 such as a semiconductor wafer.

The electrostatic chuck 118 is formed in the same shape and size as the shape of the substrate 114 to be mounted on the upper surface, but is not particularly limited. For example, when the substrate 114 is a semiconductor wafer, it is preferable that the cross section is formed in a cylindrical shape similar to the shape of the wafer and the diameter is formed to be approximately similar to the wafer diameter. The electrostatic chuck 118 is provided with an electroconductive member (not shown) inside, and the electroconductive member is connected to the high voltage direct current power supply 138 to apply and hold the substrate 114 by applying a high voltage. In this case, the electrostatic chuck 118 may maintain the substrate 114 by a vacuum force or a mechanical force in addition to the electrostatic force.

A ring-shaped focus ring 134 is provided at an edge of the lower electrode portion 152 to surround the lower electrode plate 116 and the electrostatic chuck 118. The focus ring 134 is made of a ceramic insulator such as aluminum nitride. The focus ring 134 connects the plasma to the inside thereof to increase the incident efficiency of the plasma active species to the surface of the substrate 114. The upper portion of the focus ring 134 may be configured to be lower than the mounting surface of the substrate 114 of the electrostatic chuck 118.

In addition, a porous exhaust plate 124 is connected to an outer circumferential surface of the lower electrode part 152 to smooth the flow of the exhaust gas and to confine the plasma in a predetermined section. The porous exhaust plate 124 is connected to the inner wall of the vacuum chamber 110 whose outer peripheral surface is grounded, and the inner peripheral surface is connected to the lower electrode portion 152 to electrically connect the vacuum chamber 110 and the lower electrode portion 152. By doing so, it serves to easily form a path of a high frequency current.

A buffer chamber 154 is disposed below the lower electrode unit 152 to exhaust the process gas. The buffer chamber 154 electrically connects the vacuum chamber 110 and the lower electrode portion 152, as in the role of the porous exhaust plate 124, and also the vacuum chamber 110 and the lower electrode portion 152. Supporting the load of, serves to correct the exhaust flow between the vacuum chamber 110 and the exhaust port 156.

3A is a plan view of a buffer chamber according to the present invention, and FIG. 3B shows a cross-sectional view taken along line AA ′ of FIG. 3A. 3C is a plan view illustrating a case where two or more exhaust ports are formed in the exhaust chamber as a modification of FIGS. 3A and 3B.

As shown in FIGS. 3A and 3B, the buffer chamber 154 is spaced apart by a predetermined distance from the inner support tube 158 having the inner opening 166 penetrated in the longitudinal direction at the center thereof and the outer circumferential surface of the inner support tube 158. A plurality of support 164 connecting at least an upper portion between the formed outer support tube 162, the inner support tube 158 outer circumferential surface and the outer support tube 162 inner circumferential surface, and an exhaust port provided on the outer support tube 162 outer circumferential surface 156 is comprised. In this case, an outer opening 160 is formed between the inner support tube 158 and the outer support tube 162.

The buffer chamber 154 is made of stainless steel to support heavy loads of the process chamber and the lower electrode portion 152 in the vacuum chamber 110. Through the inner opening 166 of the buffer chamber 154, an additional line such as a high frequency power source, a DC high voltage power source, a gas line and a sensor line (not shown) may be connected to the lower portion of the vacuum chamber.

In the above, although the buffer chamber 154 is formed in a circular shape, it is not limited thereto and may be variously modified. That is, the shape of the lower electrode part 152 supporting the substrate 114 and the internal space of the vacuum chamber 110 may be changed to various shapes including polygons.

In addition, the outer opening 160 of the outer circumferential surface of the inner opening 166 is formed to have a large area so that the process gas can be efficiently exhausted, and the exhaust port 156 has a side surface of the buffer chamber 154 as shown in FIG. 3B. Is attached to. In the present embodiment, one exhaust port 156 is shown on the side of the buffer chamber 154, but as shown in Figure 3c, may be formed in one or more.

The lower surface of the buffer chamber 154 is opened and opened only at the lower portion of the inner opening 166 so that various additional lines can be located, and exhaust gas can be exhausted to the exhaust port 156 provided on the side of the buffer chamber 154. The bottom surface of the outer opening 160 is closed so that it is closed. On the upper surface of the buffer chamber 154, a support 164 is formed in a space between the inner support tube 158 and the outer support tube 162. The support 164 electrically connects the process chamber in the vacuum chamber 110 and the lower electrode part 152 and fixes the inner support tube 158 and the outer support tube 162.

In addition, an O-ring may be positioned on an upper surface of the inner support tube 158 and the outer support tube 162 of the buffer chamber 154, and a screw groove 168 may be formed. The O-rings are fixed and fastened by screws and maintain the airtightness of each fastening to prevent leakage of the exhaust gas in the exhaust flow, that is, leakage.

4A to 4E are plan views schematically illustrating various types of buffer chambers.

Referring to the drawings, in the buffer chamber 154 in Figures 3a to 3c is installed four supports in a circular space, the number may be formed of one or more, the number is not limited. In addition, in order to increase the area of the exhaust port, as shown in FIGS. 4C and 4D, a predetermined through hole may be formed in the support itself. Furthermore, as shown in FIG. 4E, the support may be formed in a plate shape covering all of the upper surface of the outer opening, and then a plurality of predetermined through holes may be formed in the plate support.

In the present embodiment, the buffer chamber 154 has a stainless steel material to withstand the heavy loads of the vacuum chamber 110 and the lower electrode portion 152, but the material of the processing chamber and the bottom surface of the lower electrode portion 152 are described. It is also possible to configure the aluminum with good electrical conductivity, such as the material. The aluminum has about 30 times better electrical conductivity than stainless steel. Therefore, when the buffer chamber 154 is made of aluminum, the electrical connection between the vacuum chamber 110 and the lower electrode portion 152 can be improved to smoothly form the flow of high frequency power, and consequently, the plasma density is improved. You can.

However, since the hardness of aluminum is lower than that of stainless steel, in order to withstand the heavy loads of the processing chamber and the lower electrode unit 152, the thickness of the buffer chamber 154 is increased, or the inner support tube 158 and the outer support tube, as necessary. The upper and lower thicknesses of the support 164 connecting the 162 should be large. In addition, when the thickness of the support 164 is formed to be large, the outer opening 160 is narrowed, which is a problem for exhaust, so that a through hole having a predetermined shape may be formed on the surface of the support 164.

The material of the buffer chamber 154 is not limited to the aluminum, and any material having better electrical conductivity than stainless steel may be used.

FIG. 5 schematically shows a buffer chamber and a plasma processing apparatus equipped with the buffer chamber as another embodiment of the present invention.

Since the configuration of the upper and lower electrode portions of the plasma processing apparatus is the same as in the previous embodiment, description thereof is omitted.

As in the previous embodiment, a buffer chamber 154 is disposed below the lower electrode portion 152 of the vacuum chamber 110 to exhaust the process gas. The buffer chamber 154 electrically connects the chamber 110 and the lower electrode portion 152, as in the role of the porous exhaust plate 124, and also loads the chamber 110 and the lower electrode portion 152. While supporting the, serves to correct the exhaust flow between the chamber 110 and the exhaust port 150. However, the present embodiment further includes a lower ground plate 170 between the lower electrode portion 152 and the buffer chamfer 154.

The lower ground plate 170 is coupled to the upper surface of the lower ground plate 170 to the lower surface of the vacuum chamber 110, the lower surface of the lower ground plate 170 is fastened to the upper surface of the buffer chamber 154 It has a structure. The lower ground plate 170 is made of aluminum.

In the above structure, the lower ground plate 170 is made of aluminum having good electrical conductivity, thereby lowering electrical paths connected to the lower electrode part 152, the lower ground plate 170, and the vacuum chamber 110. Is formed. In this way, the flow of high frequency power is easily formed, and high density plasma is easily generated. In addition, even if the buffer chamber 154 is formed of stainless steel that can withstand heavy loads, as in the previous embodiment, the same effect as when the buffer chamber 154 is formed of aluminum can be obtained.

The lower ground plate 170 is not limited to aluminum, and any one may be formed as long as the electrical conductivity is better than that of stainless steel.

FIG. 6A is a plan view of a lower ground plane according to the present invention, and FIG. 6B is a sectional view taken along line BB ′ of FIG. 6A.

The lower ground plate 170 has an inner support tube 258 having an inner opening 266 formed in a longitudinal direction at the center thereof, an outer support tube 262 formed at a predetermined distance from the inner support tube 258, and an inner support tube ( 258) It is comprised by the several support stand 264 which connects at least the upper part between an outer peripheral surface and the inner peripheral surface of the outer support pipe 262. In this case, an outer opening 260 is formed between the inner support tube 258 and the outer support tube 262.

Lower ground plate 170 and buffer chamber 154 have no support 264 between inner support tube 258 and outer support tube 262, or lower ground plate 170 has no support 264 and buffer If only the chamber 154 has the support 164, the lower electrode portion 152 and the vacuum chamber 110 are electrically connected by the buffer chamber 154, and as a result, the buffer chamber 154 as in the previous embodiment. ) Has the same result as when formed from stainless steel. Accordingly, the lower ground plate 170 has the same shape as the buffer chamber 154 according to the present invention, and the lower ground plate 170 is configured in the same shape according to the various types of buffer chambers 154. In addition, in order to increase the exhaust area, the support 264 itself may be formed with a predetermined hole, and the support may be formed in a plate shape to form a through hole having a predetermined shape.

An upper surface of the lower ground plate 170 coupled to the lower surface of the process chamber and the lower electrode unit 152 in the vacuum chamber 110, and a lower ground plate 170 coupled to the upper surface of the buffer chamber 154. O-rings are installed on the lower surface of each. This prevents the exhaust gas from leaking, that is, leaks, in the flow of the exhaust gas, and maintains an airtight tightening. As shown in FIG. 6A, the O-rings are provided on the outer circumferential surface of the inner opening 266 and the outer circumferential surface of the outer opening 260, respectively, and are fastened to the screw groove 268 through screws.

Next, the processing operation of the semiconductor substrate using the plasma processing apparatus of the above-described configuration will be described. After opening the gate valve G, the substrate 114 is loaded into the vacuum chamber 110. The high voltage is applied from the high voltage direct current power source 138 to the electrostatic chuck 118 so that the substrate 114 is held by the electrostatic chuck 118 by the constant power. Then, it is supplied from the gas supply source 130 via the process gas supply line controlled by predetermined temperature and flow volume. The supplied gas is uniformly discharged from the gas hole 142 of the upper electrode plate 144 toward the substrate 114, and the substrate 144 is adjusted to a desired temperature.

Thereafter, high frequency power is applied to the upper electrode part 112 from the second high frequency power supply 120. As a result, a high frequency electric field is generated between the upper and lower electrodes 112 and 152 so that the processing gas supplied from the upper electrode part 115 is converted into plasma. In addition, the high frequency power is applied from the first high frequency power supply 150 to the lower electrode portion 152 to increase the plasma density near the surface of the substrate 114. By the high frequency power from these upper and lower electrode portions 112 and 152, the processing gas generates a high density plasma. At this time, between the vacuum chamber 110 and the exhaust pipe, the buffer chamber 154 corrects the exhaust flow, and exhaust gas is discharged with a uniform flow to keep the gas flow and pressure inside the vacuum chamber 110 constant. Plasma processing such as dry etching is performed by such a high density plasma. When the plasma processing is finished, the power supply from the high voltage DC power supply 138 and the high frequency power supply 120 and 150 is stopped, and the substrate 114 is carried out to the outside of the vacuum chamber 110 through the loading / unloading port G.

As described above, the exhaust device and the plasma processing device of the semiconductor device according to the present invention include a vacuum chamber and a buffer chamber and an exhaust port which are engaged with the lower surface of the lower electrode portion. Therefore, the present invention has the effect of obtaining a smooth gas flow by maintaining a constant pressure while maintaining a uniform flow of the process gas.

In addition, the present invention has an effect of uniformizing the ground potential leading to the lower electrode portion, the lower ground plate, and the processing chamber by the lower ground plate connected to the buffer chamber.

In addition, the present invention has the effect of improving the yield of the process by generating a high-efficiency, high-density plasma inside the vacuum chamber.

Claims (15)

With vacuum chamber, An upper electrode portion located above the vacuum chamber; A lower electrode part facing the upper electrode part and connected to a plurality of additional lines at a lower part thereof; Located in the lower surface of the vacuum chamber, the exhaust port is formed on one side, the buffer chamber formed with an opening so that the plurality of additional lines can pass Plasma processing apparatus comprising a. The buffer chamber of claim 1, wherein the buffer chamber includes an inner support tube, an outer support tube surrounding the inner support tube and spaced a predetermined distance from the inner support tube, and at least one support connected between the outer circumferential surface of the inner support tube and the inner circumferential surface of the outer support tube. Plasma processing apparatus, characterized in that. The plasma processing apparatus of claim 2, wherein the opening is formed at the center of the inner support tube, and the exhaust port is provided at an outer circumferential surface of the outer support tube. The plasma processing apparatus of claim 2, wherein the support unit connects an upper portion of the inner circumferential surface of the inner support tube and an inner circumferential surface of the outer support tube. The plasma processing apparatus of claim 4, wherein the support further comprises a through hole formed through the top and bottom. The plasma processing apparatus according to any one of claims 1 to 4, wherein an O-ring is provided between the buffer chamber and the vacuum chamber. The plasma processing apparatus of any one of claims 1 to 4, wherein the buffer chamber is made of stainless steel or aluminum. The plasma processing apparatus of any one of claims 1 to 4, wherein a plurality of exhaust ports are formed on a side surface of the buffer chamber. The plasma processing apparatus according to any one of claims 1 to 5, wherein a lower ground plate is further provided between the vacuum chamber and the buffer chamber. The method of claim 9, wherein the lower ground plate includes an inner support portion through which an opening is formed in the center, an outer support portion formed at a predetermined distance from an outer circumferential surface of the inner support portion, and a support portion connecting the inner circumferential surface of the inner support portion and the inner circumferential surface of the outer support portion to each other. Plasma processing apparatus, characterized in that. The plasma processing apparatus of claim 10, wherein a plurality of the support units are formed. The plasma processing apparatus of claim 11, wherein the support portion covers an upper portion of the outer support portion. The plasma processing apparatus of claim 12, further comprising a through hole formed in the support part. The support is a plate-shaped cover the upper portion of the outer opening and the support is a plasma processing apparatus, characterized in that the upper and lower through-holes of a predetermined shape is formed. The plasma processing apparatus of claim 10, wherein an O-ring is provided between the vacuum chamber, the lower ground plate, and the buffer chamber, respectively. The plasma processing apparatus of claim 10, wherein an electrical conductivity of the lower ground plate is higher than that of a buffer chamber.

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