JP2005033152A - Plasma processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processor capable of preventing a leak discharge from occurring and performing a good plasma discharge processing. <P>SOLUTION: An insulator holder 21 is provided under a metal gas-leading unit 10 of a plasma processor M1, and a group of plural electrodes 31, 32 is accommodated in this insulator holder 21. Upper and lower plates 22, 23 of the holder 21 are made of ceramics. A primary gasket 51 is pinched between the upper plates 22 and the electrode group, and a secondary gasket 52 is pinched between the upper plates 22 and the lower plates 23 of the electrode group. Further, a tertiary gasket 53 is pinched between a gas-leading unit 10 and the upper plates 22. These gaskets 51 to 53 form a sheet state having an area mostly spreading the whole between members which pinch the gaskets, and consist of polytetrafluoroethylene. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plasma processing apparatus that performs surface processing such as plasma CVD.

  For example, the plasma processing apparatus described in Patent Document 1 includes a pair of electrodes and a holder that accommodates and holds these electrodes. The holder is made of an insulating material ceramic, whereby the electrodes are insulated. A gas introduction member is provided on the upper side of the holder, and a process gas supply source is connected to the gas introduction member. Process gas from this supply source is introduced between the electrodes through the gas passages of the gas introduction member and the holder upper plate, and is converted into plasma by application of an electric field. This plasma-ized gas is blown out from the blow-out port of the holder lower plate, and hits the object to be processed. Thereby, the surface treatment of a to-be-processed object is made | formed.

JP-A-9-92493

  The ceramic holder is rich in heat resistance and can sufficiently control the temperature of the process gas. On the other hand, when a high voltage is applied, leakage discharge (plasma leakage) may occur between the electrodes along the inner surface of the ceramic holder. As a result, a stable glow discharge for converting the process gas into plasma cannot be obtained. In particular, the possibility is high in an atmospheric pressure plasma processing apparatus that performs processing in a substantially normal pressure environment.

  In order to solve the above problems, a plasma processing apparatus according to the present invention includes a group of a plurality of electrodes for plasma processing and a ceramic plate addressed to a side portion of the electrode group. In a plasma processing apparatus comprising a holder for insulating and holding the electrode, a thin plate-shaped insulating resin packing (gasket) having an area extending over almost the entire area is interposed between the electrode group and the plate. It is characterized by being.

  According to this characteristic configuration, the electrode can be reliably insulated with a holder having a ceramic plate and heat resistance can be ensured to achieve uniform processing. Leakage discharge can be prevented and good plasma discharge treatment can be performed. It is desirable that this leakage discharge preventing packing is disposed at least between the plate across the plurality of electrodes in the holder and the group of the plurality of electrodes.

Gas passages are formed between adjacent electrodes of the electrode group, and ceramic plates of the holder are respectively arranged on the upstream side and the downstream side of the electrode group (so as to straddle between the electrodes). A gas passage is formed, the gas passage of the upstream plate serves as an introduction passage between the electrodes of the process gas, and the gas passage of the downstream plate serves as a blow-out port, and the upstream plate and the electrode group serve as the packing. A first packing (first gasket) is interposed between the electrodes, and a second packing (second gasket) is interposed between the electrode group and the downstream plate, and the first and second packings each include an electrode group. It is desirable that a communication passage connecting the gas passages of the plate and the plate is formed.
Thereby, the flow of the process gas can be reliably ensured, and leak discharge can be prevented on both the upstream side and the downstream side of the electrode.

A metal gas introduction member is provided on the opposite side (upstream side) to the electrode group of the upstream plate, and a gas passage connected to a process gas supply source is formed in the gas introduction member. Between the gas introduction member and the upstream plate, there is interposed a third packing made of insulating resin (third gasket) having a thin plate shape having an area extending over almost the entire area of the gas, and the gas is supplied to the third packing. It is desirable that a communication path that connects the gas passages of the introduction member and the upstream plate is formed.
This can surely prevent gas leakage between the gas introduction member and the upstream plate of the holder, improve the processing efficiency, and ensure that current leaks to the metal gas introduction member via the upstream plate. Can be prevented.

In an apparatus for film formation, a process gas supply source includes a source gas supply source including a film raw material, and a plasma gas supply source that is excited so that the raw material can be formed into a film by applying an electric field. In addition, a source gas passage (including the gas passage and the communication passage) and a plasma gas passage (same as above) are formed separately at least upstream (including the two supply sources) including the electrode group. In addition, it is desirable to apply an electric field only to the plasma gas passage in the electrode group.
As a result, only the plasma gas can be excited / plasmaized by applying an electric field and then contacted with the source gas downstream from the electrode group to form a film, thereby preventing the film from sticking to the electrode. This can save maintenance work.

In the film forming apparatus, the electrode group includes a plurality of electric field applying electrodes connected to the electric field applying means and a grounded ground electrode, and the source electrode is between the electric field applying electrodes or the ground electrodes. It is desirable that a gas passage be formed between the electric field applying electrode and the ground electrode.
As a result, only the plasma target gas can be excited and plasmad by applying an electric field with certainty, and no electric field can be applied to the source gas.

  The insulating resin is preferably polytetrafluoroethylene. As a result, leak discharge can be prevented more reliably.

The above-described packing (including the first packing, the second packing, and the third packing) is made of non-porous (porosity is substantially zero, dense structure, solid structure) insulating resin to prevent internal ventilation. It is desirable to have a part. As a result, leak discharge can be prevented more reliably.
The non-porous insulating resin is preferably non-porous polytetrafluoroethylene. Thereby, leak discharge can be prevented more reliably.
The packing (including the first packing, the second packing, and the third packing) integrally wraps the contents made of porous (fibrous) polytetrafluoroethylene with a skin made of non-porous polytetrafluoroethylene. Thus, it is more desirable that the epidermis is the ventilation blocker. As a result, leak discharge can be prevented more reliably, and the ceramic plate can be prevented from being damaged by the sealing pressure.

The present invention is particularly effective in a plasma processing apparatus performed in an environment of substantially normal pressure (pressure near atmospheric pressure). The substantially normal pressure in the present invention refers to a range of 1.333 × 10 ^{4 to} 10.664 × 10 ⁴ Pa. In particular, the range of 9.331 × 10 ^{4 to} 10.9797 × 10 ⁴ Pa is preferable because the pressure adjustment is easy and the apparatus configuration is simple.

  According to the present invention, not only can the electrode be reliably insulated with a holder having a ceramic plate, heat resistance can be ensured to achieve uniform processing, but leakage discharge between the electrode group and the plate can be prevented. Therefore, a favorable plasma discharge treatment can be performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an atmospheric pressure plasma CVD apparatus M1 (plasma processing apparatus) according to an embodiment of the present invention. The atmospheric pressure plasma CVD apparatus M1 includes a nozzle head 1 supported by a gantry (not shown), gas supply sources 2A, 2B, 2C connected to the nozzle head 1, and a pulse power source 3. Below the nozzle head 1, a thin plate-like workpiece (processing object) W such as a silicon wafer is disposed. The workpiece W is conveyed in the front-rear direction indicated by the arrows in FIG. Of course, the workpiece W may be fixed and the nozzle head 1 may be moved. The plasma CVD apparatus M1 is formed by vapor-depositing amorphous silicon or the like on the upper surface of the work W under normal pressure.

  In FIG. 1, the thickness of the workpiece W is exaggerated. 5-30 mm is preferable and, as for the distance (working distance) between the nozzle head 1 and the workpiece | work W, 5-20 mm is more preferable. If it is less than 5 mm, the gas phase reaction is not sufficient, and it is difficult to obtain the desired film characteristics. If it exceeds 30 mm, the gas phase reaction becomes excessive and particles may be generated.

  The workpiece W is heated (temperature adjusted) by a workpiece heater (processing object temperature adjusting means) (not shown) and then subjected to a film forming process. The heating temperature is preferably about 200 to 500 ° C. If it is not in this temperature range, no film is formed, and even if a film is formed, good film quality cannot be obtained. In addition, a heating system is not ask | required.

  The source gas supply source 2A of the atmospheric pressure plasma CVD apparatus M1 stores the silicon source, the dopan source and the carrier gas separately, mixes them at a predetermined flow rate ratio, generates a source gas, and sends it to the gas supply pipe 2d. It has become. The original liquid source is vaporized using a vaporizer. They may be mixed after being vaporized independently, or may be vaporized after being mixed in a liquid state.

As the silicon source, for example, alkoxy compounds such as TMOS, TEOS, and MTMOS, and siloxane compounds such as HMDSO and TMCTS are used.
Examples of the dopan sauce include phosphate esters such as TEOP and TMOP, phosphite esters such as TMP and TEP, alkyl borates such as TEB and TMB, and alkoxygermanium such as TMGe and TEGe.
For example, O ₂ , N ₂ , or N ₂ O is used as the carrier gas.

The plasma gas supply source 2B stores a plasma gas that is turned into plasma by applying an electric field.
As the plasma gas, for example, any one of O ₂ , N ₂ O, NO ₂ , NO, H ₂ O, and O ₃ , or a mixture selected from a plurality of these is used.

For example, N ₂ is stored as curtain gas in the curtain gas supply source 2C.
When the curtain gas and the source carrier gas are the same material, these gas tanks may be shared.

  As shown in FIG. 2, the pulse power source 3 (electric field applying means) outputs a pulse voltage to the electrode 31 described later. It is desirable that the rise time and / or fall time of this pulse is 10 μs or less, the pulse duration is 200 μs or less, the electric field strength is 1-1000 kV / cm, and the frequency is 0.5 kHz or more.

The nozzle head 1 of the atmospheric pressure plasma CVD apparatus M1 will be described.
As shown in FIG. 1, the nozzle head 1 has a gas introduction unit 10, a discharge processing unit 20, and an outer casing 40, and extends long in the left-right direction perpendicular to the paper surface of FIG. 1 (see FIG. 2). ).

  The outer casing 40 of the nozzle head 1 is made of a metal such as stainless steel, and surrounds the gas introduction unit 10 and the discharge processing unit 20 from front, rear, left and right. The inside of the outer casing 40 is a double cavity, the inner cavity constitutes an exhaust duct 41, and the outer cavity constitutes a curtain gas outlet duct 42. Both of these ducts 41 and 42 are opened downward. The upper end portion of the exhaust duct 41 is connected to the exhaust pump 4 via the suction pipe 4a. A curtain gas supply pipe 2f from the curtain gas supply source 2C is connected to the upper end of the curtain gas outlet duct 42.

  In the gas introduction unit 10, three rows of gas passages 10f, 10m, and 10r are formed side by side (right and left in FIG. 1). A source gas supply pipe 2d from the source gas supply source 2A is connected to the upper end of the central gas passage 10m. The plasma gas supply pipe 2e from the plasma gas supply source 2B is branched and connected to the gas passages 10f and 10r on both the front and rear sides. In addition, although detailed illustration is abbreviate | omitted, the gas introduction unit 10 is comprised by laminating | stacking the some metal flat plate (gas introduction member) which consists of aluminum, stainless steel, etc. up and down. Each metal flat plate is formed with a large number of small holes distributed left and right, slit-like chambers extending left and right, and the like arranged in three rows in the front and rear. The gas passages 10f, 10m, and 10r are configured by connecting small holes, chambers, and the like between the metal flat plates stacked one above the other in each row. The gas from each of the supply pipes 2d and 2e is made uniform in the left-right direction by the gas passages 10f, 10m, and 10r made of the small holes and chambers. Between the laminated surfaces of the metal flat plates, a gasket having the same configuration as gaskets 51 to 53 described later is sandwiched.

  The gas introduction unit 10 is provided with a heater (gas introduction unit temperature adjusting means) (not shown). Thereby, the gas introduction unit 10 is heated (temperature adjusted) in a range of, for example, about 50 to 200 ° C. If it is less than 50 degreeC, there exists a possibility that the vaporized silicon source and dopan sauce may re-liquefy, and if it exceeds 200 degreeC, there exists a possibility of causing a thermal reaction.

The discharge processing unit 20 is disposed below the gas introduction unit 10.
As shown in FIGS. 1 and 2, the discharge processing unit 20 includes an electrode group including four (plural) electrodes 31 and 32, a holder 21 that holds and holds the electrodes 31 and 32, and the holder. 21 has a metal frame 26 that surrounds the front, rear, left and right.

  The upper end portion of the frame 26 is fixed to the gas introduction unit 10 with bolts (not shown). As shown in FIG. 1, the outer peripheral portion of the lower end surface of the frame 26 is placed so as to be hooked on the inner flange 43 of the outer casing 40. Thereby, the discharge processing unit 20 and the gas introduction unit 10 are supported by the outer casing 40.

  Each of the electrodes 31 and 32 of the discharge processing unit 20 has a long and narrow plate shape with the width direction facing up and down. For example, stainless steel is used as the material of the electrodes 31 and 32, but is not limited thereto, and other conductive metals such as aluminum may be used.

  The four electrodes 31 and 32 are arranged at intervals in the front-rear direction. The left and right elongated slit-shaped gaps between the adjacent electrodes 31 and 32 are gas passages 30f, 30m, and 30r, respectively. The front-rear width (distance between the electrodes 31, 32) of these gas passages 30f, 30m, 30r is preferably 0.1 to 50 mm, and more preferably 5 mm or less.

  As shown in FIG. 2, a power supply line 3 a from the power supply 3 is connected to one end (for example, the left end) of the two central electrodes 31. Thus, the central two electrodes 31 are electric field application electrodes. Therefore, an electric field is not applied to the central gas passage 30m.

  The ground wire 3b is connected to the other end portions (for example, right end portions) of the two electrodes 32 on both the front and rear sides. By grounding the ground line 3b, the electrodes 32 on both sides serve as ground electrodes. Thereby, an electric field is applied to the gas passages 30f and 30r on both sides by the voltage supply from the power supply 3, and the plasma passages are formed.

Although detailed illustration is omitted, a solid dielectric layer is coated by, for example, thermal spraying on the plasma forming spaces 30f, 30r forming surfaces of the electrodes 31, 32, and the upper and lower surfaces. The dielectric constant of the solid dielectric is preferably 2 or more, and more preferably 10 or more. As the material of the solid dielectric, a resin such as polytetrafluoroethylene, a metal oxide such as Al ₂ O ₃ , or a double oxide such as BaTiO ₃ is used. The solid dielectric layer may be a single layer or a laminated structure of a plurality of layers. For example, it is preferable to coat a BaTiO ₃ layer on the side of the metal surface constituting the electrodes 31 and 32 and coat an Al ₂ O ₃ layer on the outer side thereof to ensure a dielectric constant of 10 or more.

  Although illustration is omitted, a temperature control refrigerant path is formed in each of the electrodes 31 and 32, and heating of the electrodes 31 and 32 (temperature adjustment) in a range of, for example, about 50 to 200 ° C. by passing the refrigerant therethrough. ) Is now possible. If it is less than 50 degreeC, there exists a possibility that the vaporized silicon source and dopan sauce may reliquefy. The upper limit of 200 ° C. takes into account the difference in thermal expansion between the stainless steel constituting the electrodes 31 and 32 and the solid dielectric layer.

  As shown in FIGS. 1 and 2, the holder 21 includes a plate 22 straddling between the upper (upstream) surfaces of the four electrodes 31, 32, a plate 23 straddling between the lower (downstream) surfaces, It has the side plate 24 arrange | positioned forward and backward, and the end cap 25 arrange | positioned at right and left.

  As shown in FIG. 2, three plate-like spacers 27 are provided on the left and right end caps 25 made of insulating resin. By inserting the spacer 27 into the gap between the adjacent electrodes 31 and 32, the distance between the electrodes 31 and 32 is maintained.

  Each plate 22, 23, 24 before and after the holder 21 is made of ceramic (insulating material). Thereby, the electrodes 31 and 32 are insulated. The material of the ceramic is not particularly limited, but the dielectric constant is preferably 20 or less, and more preferably 10 or less. When the dielectric constant exceeds 20, current may leak locally to the surrounding metal members.

  As shown in FIG. 1, the left and right elongated upper plate 22 is sandwiched from above and below by the gas introduction unit 10 and the electrodes 31 and 32. In the plate 22, three gas passages 22f, 22m, and 22r are formed. The gas passages 22f, 22m, and 22r extend in the left-right direction orthogonal to the paper surface of FIG. 1 and are spaced apart from each other.

  The front gas passage 22f is connected to the front gas passage 10f of the gas introduction unit 10 and is inclined downward and connected to the gas passage 30f between the front electrodes 31 and 32. As a result, the gas passage 22f serves as a path for introducing the plasma target gas into the interelectrode passage 30f.

  The central gas passage 22 m is continuous with the central gas passage 10 m of the gas introduction unit 10 and extends directly below, and is continuous with the gas passage 30 m between the central electrodes 31. Thereby, the gas passage 22m is an introduction path for the source gas to the inter-electrode passage 30m.

  The rear gas passage 22r is connected to the rear gas passage 10r of the gas introduction unit 10 and is inclined downward and connected to the gas passage 30r between the rear electrodes 31 and 32. Thereby, the gas passage 22r serves as an introduction path for the plasma-target gas to the interelectrode passage 30r.

  As shown in FIG. 1 and FIG. 3, three gas passages 23 f, 23 m, 23 r penetrating in the vertical thickness direction are formed in the left and right elongated bottom plate 23 of the holder 21. The gas passages 23f, 23m, and 23r are formed in a slit shape and extend left and right, and are spaced apart from each other.

The front gas passage 23f is connected to the gas passage 30f between the front electrodes 31 and 32, and serves as a blowout hole for the plasma gas.
The central gas passage 23m is connected to the gas passage 30m between the central electrodes 31 and serves as a source gas blowing hole.
The rear gas passage 23r is connected to the gas passage 30r between the rear electrodes 31 and 32, and serves as a blowout hole for plasma gas.

The most characteristic part of the present invention will be described.
As shown in FIG. 1, a first gasket 51 (first packing) is interposed between the lower surface of the upper plate 22 of the holder 21 and the upper surfaces of the electrodes 31 and 32. The gasket 51 is made of an insulating resin such as polytetrafluoroethylene. As shown in FIG. 1 and FIG. 4, the gasket 51 is formed in an elongated thin plate shape and extends substantially between the plate 22 and the electrodes 31 and 32. The thickness of the gasket 51 is preferably larger than 1 mm and about 2 mm. If it is 1 mm or less, the effect of preventing the leak discharge described later cannot be expected.

  The first gasket 51 is formed with three communication passages 51f, 51m, and 51r. The communication passages 51f, 51m, and 51r are formed in a slit shape and extend left and right, and are spaced apart from each other.

The front communication passage 51f connects the front passage 22f of the upper plate 22 and the front interelectrode passage 30f.
The central communication passage 51m connects the central passage 22m of the upper plate 22 and the central inter-electrode passage 30m.
The rear communication passage 51r connects the rear passage 22r of the upper plate 22 and the rear inter-electrode passage 30r.

  As shown in FIGS. 1 and 3, a second gasket 52 (second packing) is interposed between the lower surfaces of the electrodes 31 and 32 and the upper surface of the lower end plate 23 of the holder 21. The gasket 52 is made of an insulating resin such as polytetrafluoroethylene, like the first gasket 51, and has a thin and long thin plate shape that extends between the electrodes 31 and 32 and the plate 23. The thickness of the gasket 52 is preferably larger than 1 mm and about 2 mm.

  In the second gasket 52, three communication passages 52f, 52m, and 52r are formed. The communication passages 52f, 52m, and 52r are formed in a slit shape and extend left and right, and are spaced apart from each other.

The front communication path 52 f connects the front interelectrode path 30 f and the front path 23 f of the lower end plate 23.
The central communication passage 52 m connects the central electrode passage 30 m and the central passage 23 m of the lower end plate 23.
The rear communication passage 52r connects the rear interelectrode passage 30r and the rear passage 23r of the lower end plate 23.

  Further, as shown in FIG. 1, a third gasket 53 (third packing) is provided between the lower surface of the lowermost metal flat plate (gas introduction member) of the gas introduction unit 10 and the upper surface of the upper plate 22 of the holder 21. Is intervened. The gasket 53 is also made of an insulating resin such as polytetrafluoroethylene, similar to the gaskets 51 and 52, and extends in a thin plate shape between the gas introduction unit 10 and the electrodes 31 and 32. The thickness of the gasket 53 is preferably larger than 1 mm and about 2 mm.

  The third gasket 53 is formed with three communication passages 53f, 53m, and 53r. The communication passages 53f, 53m, and 53r are slit-shaped and extend left and right, and are disposed apart from each other in the front-rear direction.

The front communication passage 53 f connects the front passage 10 f of the gas introduction unit 10 and the front passage 22 f of the plate 22.
The central communication passage 53 m connects the central passage 10 m of the gas introduction unit 10 and the central passage 22 m of the plate 22.
The rear communication passage 53r connects the rear passage 10r of the gas introduction unit 10 and the rear passage 22r of the plate 22.

The operation of the atmospheric pressure plasma CVD apparatus M1 having the above configuration will be described.
The plasma target gas from the supply source 2B is made uniform in the left and right through the pipe 2e in the gas passages 10f and 10r of the introduction unit 10, and then the communication passages 53f and 53r of the gasket 53 and the gas passages 22f and 22r of the plate 22. Then, the gas passes through the communication passages 51f and 51r of the gasket 51 and is introduced into the front and rear inter-electrode passages 30f and 30r.

  A pulse voltage from the pulse power source 3 is applied between the electrodes 31 and 32. As a result, a pulse electric field is generated in the passages 30f and 30r between the front and rear electrodes 31 and 32 to cause glow discharge, and the plasma gas is turned into plasma (excited and activated). The plasma-generated plasma gas passes through the communication passages 52f and 52r of the gasket 52 and the gas passages 23f and 23r of the plate 23 in order, and is blown downward from the gas passages 23f and 23r. Since the plasma target gas does not contain a film raw material, it does not adhere to the surfaces of the electrodes 31 and 32 where the passages 30f and 30r are formed even if the plasma is gasified in the interelectrode passages 30f and 30r.

  Simultaneously with the circulation of the plasma gas, the source gas from the supply source 2A is made uniform in the left and right directions in the gas passage 10m of the introduction unit 10 via the pipe 2d, and then the communication passage 53m of the gasket 53, the plate 22 The gas passage 22m and the communication passage 51m of the gasket 51 are sequentially introduced into the central interpolar electrode passage 30m. Since no electric field is applied in the interelectrode passage 30m, the source gas passes through without being converted into plasma. Therefore, no film adheres to the surface of the electrode 31 where the passage 30m is formed. Then, the source gas sequentially passes through the communication passage 52m of the gasket 52 and the gas passage 23m of the plate 23 and is blown downward from the gas passage 23m.

  As shown by the arrow line in FIG. 1, the source gas blown out from the central passage 23m flows between the nozzle head 1 and the workpiece W in two front and rear hands. Then, it comes into contact with the plasma-treated gas from the front and rear passages 23f and 23r. Thereby, a reaction of the source gas occurs, and a film can be formed on the workpiece W.

  Here, by heating the gas introduction unit 10 and the electrodes 31 and 32 and maintaining the process gas (source gas and plasma gas) at a suitable temperature (50 to 200 ° C.), good film quality can be obtained. The film forming speed can also be improved. Further, not only can the gas be made uniform left and right by the passages 10f, 10m, and 10r of the gas introduction unit 10, but the uniformity of the gas flow can be reliably maintained by using a heat-resistant ceramic as the holder 21 to prevent thermal deformation. The film thickness of the workpiece W can be made uniform uniformly. As a result, the yield of film formation can be improved.

During the film forming process, curtain gas from the supply source 2C is blown out from the duct 42 of the outer casing 40 through the pipe 2f. Thereby, a gas curtain can be formed between the periphery of the nozzle head 1 and the workpiece W, and leakage of process gas can be prevented.
Thereafter, the gas is sucked into the exhaust duct 41 and exhausted by the exhaust pump 4.

In the atmospheric pressure plasma CVD apparatus M1, it is possible to reliably prevent discharge from leaking from the electrode group when the electric field is applied.
That is, between the electrodes 31 and 32 and the upper plate 22, the process gas can be prevented from leaking by the first gasket 51 made of insulating resin, and leak discharge can be prevented.
Similarly, between the electrodes 31 and 32 and the lower plate 23, leakage of process gas can be prevented by the second gasket 52 made of insulating resin, and leakage discharge can be prevented.
Further, between the upper plate 22 and the gas introduction unit 10, the process gas leak can be prevented by the third gasket 53 made of insulating resin, and the leak discharge can be prevented.
By constituting the gaskets 51 to 53 with polytetrafluoroethylene among insulating resins, it is possible to more reliably prevent leak discharge.
As a result, a stable glow discharge can be obtained in the electrode group under normal pressure. As a result, good film quality can be stably obtained, and the yield can be further improved.

Next, another embodiment of the present invention will be described.
In this embodiment, the structure shown in FIG. 5 is used as the first to third gaskets of the atmospheric pressure plasma CVD apparatus M1.
As shown in FIG. 5A, the first gasket 51X (first packing) sandwiched between the upper plate 22 and the electrode group includes a content 51a and the surface (upper and lower surfaces, peripheral end surface, And an outer skin 51b (ventilation preventing portion) covering the whole of the passage 51f, 51m, 51r side inner peripheral surface). The contents 51a are made of porous polytetrafluoroethylene. On the other hand, the skin 51b is made of nonporous polytetrafluoroethylene. The skin 51b is laminated integrally on the surface of the contents 51a.

  As shown in FIG. 5B, the second gasket 52X (second packing) sandwiched between the electrode group and the lower plate 23 includes a content 52a and the surface (upper and lower surfaces, peripheral end surface) of the content 52a. , And an outer skin 52b (venting portion) covering the entire inner peripheral surface of the passages 52f, 52m, and 52r). The contents 52a is made of porous polytetrafluoroethylene, and the skin 52b is made of nonporous polytetrafluoroethylene. The skin 52b is laminated integrally on the surface of the contents 52a.

As shown in FIG. 5 (c), the third gasket 53X (third packing) sandwiched between the gas introduction unit 10 and the upper plate 22 includes a content 53a and the surface (upper and lower surfaces, peripheral surfaces) of the content 53a. It is comprised with the skin 53b (ventilation prevention part) which covers the whole end surface and the inner peripheral surface by the side of the channel | paths 53f, 53m, and 53r). The contents 53a are made of porous polytetrafluoroethylene, and the skin 53b is made of nonporous polytetrafluoroethylene. The epidermis 53b is integrally laminated on the surface of the contents 53a.
5A to 5C, the thickness of the gaskets 51X, 53X, 53X is exaggerated.

  According to this embodiment, minute leaks into the gaskets 51X, 53X, 53X can also be prevented by the nonporous skins 51b, 52b, 53b. In addition, since the contents 51a, 52a and 53a are porous, they can be fitted to the sealed members 10, 22, 31, 32 and 23 without increasing the sealing pressure, and can be reliably sealed. As a result, leakage discharge can be prevented more reliably, and the ceramic plates 22 and 23 can be prevented from being damaged by the sealing pressure.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, you may comprise the whole of each packing with the polytetrafluoroethylene of complete solid structure. (The whole packing may be a non-porous ventilation blocker.)
If at least the first and second packings are present, leakage discharge can be largely prevented. Depending on the device configuration, the packing interposed between the gas introduction member and the upstream plate may be a packing that can prevent gas leakage instead of the third packing according to the present invention. .
In the lower plate 23, the source gas passage 23m and the plasma gas passages 23f and 23r may be joined so that the source gas and the plasma gas are mixed and mixed and blown out from a single outlet.
The present invention can be applied not only to glow discharge but also to plasma treatment by corona discharge or creeping discharge, and can be applied not only to atmospheric pressure but also to plasma treatment under reduced pressure. It can be applied to various plasma processes such as quality, etching and ashing.

Examples of the present invention will be described. Needless to say, the present invention is not limited to the following examples.
First, Example 1 will be described.
Plasma CVD was performed using the apparatus shown in FIG. The source gas silicon source used was TMOS 0.25 g / min, the dopan source used TMOP 0.1 g / min, and the carrier gas used N ₂ 10 slm. As the plasma gas, O _{2 20} slm was used. An 8-inch silicon wafer was used as the workpiece W, and the set temperature was 350 ° C. The set temperature of the gas introduction unit 10 was 150 ° C., and the set temperature of the electrodes 31 and 32 was 130 ° C. The rise time of the pulse applied by the pulse power source 3 was 6 μs, the electric field strength was 25 kV / cm, the frequency was 5 kHz, and the pulse duration was 8 μs. The thicknesses of the polytetrafluoroethylene gaskets 51 to 53 were both 2 mm. Al ₂ O ₃ was used for the ceramic constituting the plates 22 to 24 of the holder 21.

As a result, no leak discharge was observed, and it was confirmed that a stable glow discharge can be obtained. The deposition rate on the 8-inch silicon wafer was 2500 Å / min. When the film thickness was measured at 225 points on the wafer using an optical film thickness meter and the film thickness uniformity was determined by the following formula, it was ± 3%.
Film thickness uniformity = (maximum film thickness−minimum film thickness) / (average film thickness) × 100 (%)

Next, Example 2 will be described.
Plasma CVD was performed in the same manner as in Example 1 except that the third gasket 53 between the gas introduction unit 10 and the plate 22 was omitted.
As a result, as in Example 1, the occurrence of leak discharge was not confirmed. The film formation rate was lower than that of Example 1 and was 2000 kg / min. This is considered to be due to gas leakage between the gas introduction unit 10 and the plate 22.

Hereinafter, a comparative example will be described.
[Comparative Example 1]
Plasma CVD was performed in the same manner as in Example 1 except that the first gasket 51 between the upper plate 22 of the holder 21 and the electrodes 31 and 32 was omitted.
As a result, leak discharge occurred between the electrodes 31 and 32 via the plate 22. For this reason, the glow discharge was not stable and sufficient film formation was not possible.

[Comparative Example 2]
Plasma CVD was performed in the same manner as in Example 1 except that the second gasket 52 between the electrodes 31 and 32 and the lower end plate 23 of the holder 21 was omitted.
As a result, leak discharge occurred between the electrodes 31 and 32 via the plate 23. For this reason, the glow discharge was not stable and sufficient film formation was not possible.

[Comparative Example 3]
Plasma CVD was performed in the same manner as in Example 1 except that the upper plate of the holder 21 was made of aluminum instead of the ceramic plate 22.
As a result, leak discharge occurred, glow discharge was not stable, and sufficient film formation was not possible.

[Comparative Example 4]
Plasma CVD was performed in the same manner as in Example 1 except that the plates before and after the holder 21 were made of polytetrafluoroethylene instead of the ceramic plate 24.
As a result, no leak discharge occurred, but the film formation rate was 2400 Å / min, and the film thickness uniformity was ± 10%, both of which were lower than in Example 1. This seems to be because the plate made of polytetrafluoroethylene was inferior to ceramic in terms of heat resistance and deformed.

[Comparative Example 5]
Plasma CVD was performed in the same manner as in Example 1 except that the lower end plate of the holder 21 was made of aluminum instead of the ceramic plate 23.
As a result, leak discharge occurred, glow discharge was not stable, and sufficient film formation was not possible.

[Comparative Example 6]
Plasma CVD was performed in the same manner as in Example 1 except that the lower end plate of the holder 21 was made of polytetrafluoroethylene instead of the ceramic plate 23.
As a result, no leak discharge occurred, but the film formation rate was 2400 Å / min, and the film thickness uniformity was ± 10%, both of which were lower than in Example 1. This is considered to be due to the same reason as in Comparative Example 4.

It is explanatory comment sectional drawing of the atmospheric pressure plasma CVD apparatus which concerns on one Embodiment of this invention. FIG. 2 is a plan sectional view of a discharge processing unit of the atmospheric pressure plasma CVD apparatus taken along line II-II in FIG. 1. It is a bottom view of the said discharge processing unit. It is a top view of the 1st gasket of the said normal pressure plasma CVD apparatus. The modification of a gasket is shown, (a) is a sectional view of the 1st gasket, (b) is a sectional view of the 2nd gasket, (c) is a sectional view of the 3rd gasket. It is.

Explanation of symbols

M1 atmospheric pressure plasma CVD equipment (plasma processing equipment)
DESCRIPTION OF SYMBOLS 10 Gas introduction unit 10f, 10r Gas passage 10m for plasma gas of gas introduction unit Gas passage 20 for source gas of gas introduction member Discharge treatment unit 21 Holder 22 Upper plate (upstream plate)
22f, 22r Gas passages (introduction passages) for the plasma target gas on the upper plate
Gas path (introduction path) for source gas of 22m upper plate
23 Lower end plate (downstream plate)
23f, 23r Gas passage for gas to be plasma (outlet) of lower end plate
23m Gas passage (outlet) for the source gas on the bottom plate
24 Side plates 30f and 30r Gas passage for plasma gas between different electrodes (plasmaization space)
30 m Gas path 31 for source gas between same-polarity electrodes Electric field application electrode 32 Ground electrodes 51, 51 X First gasket (first packing)
51f, 51r First gas gasket communication passage 51m First gasket source gas communication passage 52, 52X Second gasket (second packing)
52f, 52r communication path 52m for the plasma gas of the second gasket 52m, a communication path for the source gas of the second gasket 53, 53X third gasket (third packing)
53f, 53r Communication path 53m for the plasma gas of the third gasket Communication path 51a, 52a, 53a for the source gas of the third gasket Contents 51b, 52b, 53b

Claims (9)

A plurality of groups of electrodes for plasma treatment; and
A holder for holding and insulating the electrode group having a ceramic plate addressed to the side of the electrode group;
In a plasma processing apparatus comprising:
A plasma processing apparatus characterized in that a thin plate-like packing made of an insulating resin having an area extending over almost the whole is interposed between the electrode group and the plate. Gas passages are formed between adjacent electrodes of the electrode group, and ceramic plates of the holder are arranged on the upstream side and downstream side of the electrode group, respectively, and gas passages are also formed on these plates. The gas passage of the plate serves as an introduction passage between the electrodes of the process gas, and the gas passage of the downstream plate serves as an outlet,
As the packing, a first packing is interposed between the upstream plate and the electrode group, and a second packing is interposed between the electrode group and the downstream plate. The first and second packings each include an electrode group. The plasma processing apparatus according to claim 1, wherein communication passages connecting the gas passages of the plate and the plate are formed. A metal gas introduction member is provided on the opposite side to the electrode group of the upstream plate, and a gas passage connected to a process gas supply source is formed in the gas introduction member.
Between the gas introduction member and the upstream plate, there is interposed a third packing made of insulating resin having a thin plate shape having an area covering almost the whole of the gas, and the gas introduction member and the upstream plate are interposed between the gas introduction member and the upstream plate. The plasma processing apparatus according to claim 2, wherein a communication path that connects the gas paths of the side plates is formed. An apparatus for forming a film, wherein a process gas supply source includes a source gas supply source including a film raw material, and a plasma gas supply source that is excited so that the raw material can be formed into a film by applying an electric field. The source gas passage and the plasma gas passage are separately formed on the upstream side including the electrode group, and an electric field is applied only to the plasma gas passage in the electrode group. Item 4. The plasma processing apparatus according to any one of Items 1 to 3. The electrode group has a plurality of electric field application electrodes connected to the electric field application means and a plurality of grounded ground electrodes, and the electric field application is performed between the electric field application electrodes or between the ground electrodes. The plasma processing apparatus according to claim 4, wherein a passage for the plasma gas is provided between an electrode and a ground electrode. The plasma processing apparatus according to claim 1, wherein the insulating resin is polytetrafluoroethylene. The plasma processing apparatus according to claim 1, wherein the packing is made of a nonporous insulating resin and has a ventilation blocking portion that blocks internal ventilation. The plasma processing apparatus according to claim 7, wherein the non-porous insulating resin is non-porous polytetrafluoroethylene. The packing is formed by integrally wrapping a content made of porous polytetrafluoroethylene with an outer skin made of non-porous polytetrafluoroethylene, and the outer skin serves as the ventilation block. The plasma processing apparatus according to claim 7.

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