JP2005093344A - Plasma treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma treatment apparatus having a low cost plate-like dielectric substance, even if it is used for a large electrode. <P>SOLUTION: An alumina plate (first plate-like dielectric substance) 60 and an alumina plate (second plate-like dielectric substance) 61 are provided adjacent on opposite surfaces on the side of a hot electrode 11 of a ground electrode 21. Since the alumina plates 60, 61 are provided on the opposite surfaces of the ground electrode 21, a small low cost plate-like dielectric can be used for a large electrode instead of a large expensive plate-like dielectric. Since the opposite surfaces of the ground electrode 21 can be covered again by exchanging only the damaged alumina plate 60, when only the alumina plate 60 is damaged, the cost of the alumina plate can be reduced, as compared with the case when a sheet of large alumina plate is used. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plasma processing apparatus that processes an object to be processed using plasma.

Some conventional plasma processing apparatuses are provided with a plate-like dielectric on opposing surfaces of electrodes facing each other (for example, Patent Document 1).
JP 11-191500 A

  In the plasma processing apparatus of Patent Document 1, when a large electrode is used, it is necessary to use a large plate-like dielectric according to the size of the electrode. However, the cost of a large plate dielectric is high. In addition, even if only a part of the plate dielectric is damaged, it is not possible to replace only the damaged part, and the entire plate dielectric must be replaced, which increases the cost of the plate dielectric. There is a problem that it ends up.

  In order to solve the above problems, an object of the present invention is to provide a plasma processing apparatus having a plate-like dielectric material that is low in cost even when used for a large electrode.

  The plasma processing apparatus of the present invention has a pair of electrodes facing each other, and in the plasma processing apparatus for performing plasma processing on an object to be processed using plasma generated between the pair of electrodes, at least one of the pair of electrodes A first plate-like dielectric and a second plate-like dielectric adjacent to each other are provided on the facing surface of one of the electrodes.

  By providing the first plate-like dielectric and the second plate-like dielectric adjacent to each other on the opposing surfaces of the electrodes, it is possible to use a small-sized plate-like dielectric with low cost. Further, when only a part of the plate dielectric is damaged, only the plate dielectric on the side having the damaged part can be replaced, so that the cost for the plate dielectric can be reduced.

The plasma processing apparatus of the present invention is an apparatus that performs plasma processing mainly under a pressure near atmospheric pressure. Note that the pressure of near atmospheric pressure refers to a pressure of ^{1.333 × 10 4 ~10.664 × 10 4} Pa. In particular, when the pressure for plasma treatment is in the range of 9.331 × 10 ^{4 to} 10.9797 × 10 ⁴ Pa, pressure adjustment is facilitated and the configuration of the apparatus can be simplified.

Examples of the material constituting the pair of electrodes used in the plasma processing apparatus of the present invention include metals such as stainless steel, copper, iron, aluminum, titanium, tungsten, and brass. These metals may be used alone or in combination of two or more. Further, the materials used for the respective electrodes may be different from each other.
The electrode structure is preferably arranged so that the distance between the electrodes is constant in order to avoid the occurrence of discharge due to electric field concentration. Examples of the structure of such an electrode include a parallel plate type and a cylinder-to-plate type.

  The first plate-like dielectric and the second plate-like dielectric are preferably provided side by side without any gap. When the plate-like dielectrics are provided side by side without any gap, it is possible to prevent abnormal discharge from occurring from the opposing surfaces of the electrodes.

  The first plate-like dielectric and the second plate-like dielectric are preferably the same in shape. If each plate-like dielectric has the same shape, when one of the plate-like dielectrics is damaged, it is not necessary to provide various types of plate-like dielectrics for replacement, and the plate-like dielectric is applied. Cost can be reduced.

  Examples of the material constituting such a plate-like dielectric material include plate-like solid dielectric materials such as alumina, quartz, tetrafluoroethylene, and glass.

  In the plasma processing apparatus of the present invention, the first plate-like dielectric and the second plate-like dielectric are formed from a main body portion that forms a plate-like body, and from the side surface of the main body portion. And a joint portion of the first plate dielectric and the joint of the second plate dielectric so that the main surfaces of the main body portions are substantially flush with each other. It is preferable that the part is connected.

  An outer periphery from one main surface side of the plate-like dielectric material to the other main surface side through the surface of the joint portion by connecting the joint portion connecting the plate-like dielectric materials from the side surface of the main body portion. Since the distance becomes longer, the plasma processing apparatus of the present invention can attenuate the creeping discharge while the creeping discharge generated during voltage application progresses through the joint portion of the plate-like dielectric, and thus abnormal discharge due to the creeping discharge. Can be prevented.

  Moreover, it is preferable that a creeping barrier is provided between the joint portion of the first plate-like dielectric and the joint portion of the second plate-like dielectric. If a creeping barrier is provided between these joint parts, it is possible to prevent the creeping discharge from progressing on the surface of the joint part. Even if the joint portion of the second plate-like dielectric and the joint portion of the second plate dielectric are not completely in close contact with each other, the occurrence of abnormal discharge due to creeping discharge can be prevented.

The material constituting such a creeping barrier is not particularly limited as long as it is a material that can prevent the development of creeping discharge, but for example, a resin composition such as silicone rubber, fluororesin, polyimide resin, aluminum oxide, Examples thereof include metal oxides such as zirconium dioxide, and glass such as quartz and silicon dioxide.
Of these materials, a resin composition that can be easily deformed is preferable. When such a resin composition is used, the resin composition can be deformed in accordance with the shape of the joint portion, and the resin composition can be easily provided between the joint portions.

  According to the present invention, since the first plate-like dielectric and the second plate-like dielectric are provided on the opposing surfaces of the electrodes, a large-scale plate-like dielectric that is expensive with respect to a large-sized electrode can be obtained. It is possible to use a low-cost small plate dielectric without using it, and even if only a part of the plate dielectric is damaged, only the damaged plate dielectric can be replaced. The cost for the dielectric can be reduced.

  An outer periphery from one main surface side of the plate-like dielectric material to the other main surface side through the surface of the joint portion by connecting the joint portion connecting the plate-like dielectric materials from the side surface of the main body portion. Since the distance becomes longer, the plasma processing apparatus of the present invention can attenuate the creeping discharge while the creeping discharge generated during voltage application progresses through the joint portion of the plate-like dielectric, and thus abnormal discharge due to the creeping discharge. Can be prevented.

  Further, when a creeping barrier is provided between the joint portion of the first plate dielectric and the joint portion of the second plate dielectric, the creeping discharge is prevented from progressing on the surface of the joint portion. Therefore, even if the first plate dielectric joint and the second plate dielectric joint are not completely in close contact due to errors in processing accuracy or mounting accuracy, abnormal discharge due to creeping discharge is caused. Can be prevented.

A first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of a plasma processing apparatus of the present invention. 2 is a cross-sectional view of the plasma processing apparatus along the line AA in FIG. 1, and FIG. 3 is a cross-sectional view of the plasma processing apparatus along the line BB in FIG. FIG. 4 is a perspective view showing the first plate-like dielectric and the second plate-like dielectric in FIG.

The plasma processing apparatus M of the present invention has a pair of upper and lower upper units 10 and a lower unit 20.
First, the lower unit 20 will be described.

The lower unit 20 includes a base 3, an earth electrode 21, an electrode holder 22, alumina plates 60 and 61, a duct 40, and the like.
On the plate-shaped base 3, an electrode holder 22 made of an insulating resin and a pair of rails 33, 33 are fixed.

  On the upper surface (opposing surface) of the electrode holder 22 on the upper unit side, a deep recess 22x that is recessed toward the inside of the electrode holder 22 and a shallow recess 22y along the periphery of the recess 22x are formed. A ground electrode 21 is embedded. The earth electrode 21 is grounded via the ground wire 2a. A refrigerant path 21a is formed inside the earth electrode 21, and the temperature of the earth electrode 21 is adjusted by passing the refrigerant through the refrigerant path 21a. This refrigerant is sent to the refrigerant path 21a by driving a chiller 21c connected through the refrigerant pipe 21b.

The upper surface (opposite surface) on the upper unit side of the ground electrode 21 is covered with two adjacent alumina plates (first plate dielectric and second plate dielectric) 60, 61, The upper surface of the ground electrode 21 is covered with alumina plates 60 and 61. The alumina plates 60 and 61 are connected and integrated with each other, and the peripheral edges of the integrated alumina plates 60 and 61 protrude from the peripheral edge of the ground electrode 21. The alumina plates 60 and 61 are accommodated in the recess 22 y of the electrode holder 22, and the upper surfaces of the alumina plates 60 and 61 are flush with the upper surface of the electrode holder 22.
Note that the alumina plates 60 and 61 are characteristic portions of the present invention and will be described later.

  A box-shaped duct 40 that opens to the electrode holder 22 side is formed on the upper surface of the base 3. The duct 40 is connected to the vacuum pump 4 through the suction path 4a, and sucks the gas inside the duct 40.

The upper unit 10 will be described.
The upper unit 10 includes a hot electrode 11 (first electrode), an electrode holder 12, an alumina plate 13, an upper plate 14, and the like.

  The upper plate 14 is fixed to the upper surface of the electrode holder 12, and a handle 14 a is provided on a side portion of the upper plate 14. Both ends of the upper plate 14 protrude from both ends of the electrode holder 12, and side plates 31 and 31 are provided at the protruding portions. The side plates 31 and 31 are provided on the rails 33 and 33, and the side plates 31 and 31 are slidable on the rails 33 and 33 in the direction of the arrow a or the arrow b. It is slidable in the direction of a or arrow b.

  The electrode holder 12 is made of an insulating resin. On the lower surface of the electrode holder 12, a recess 12x recessed toward the inside of the electrode holder 12 and a shallow recess 12y along the periphery of the recess 12x are formed. Yes.

  A plate-like hot electrode 11 is embedded in the recess 12x, and the hot electrode 11 is connected to the power source 1 through the feeder line 1a and serves as a voltage application electrode. Moreover, the refrigerant path 11a is formed inside the hot electrode 11, and the temperature of the hot electrode 11 is adjusted by passing the refrigerant through the refrigerant path 11a. This refrigerant is sent to the refrigerant path 11a by driving a chiller 11c connected through the refrigerant pipe 11b.

An alumina plate 13 is provided on the lower surface of the hot electrode 11. The alumina plate 13 covers the lower surface of the hot electrode 11, and the periphery of the alumina plate 13 protrudes from the hot electrode 11. The alumina plate 13 is housed in the recess 12 y of the electrode holder 12, and the lower surface of the alumina plate 13 is flush with the lower surface of the electrode holder 12. The alumina plate 13 is parallel to the alumina plates 60 and 61 provided in the lower unit 20.
Here, a discharge space 50 is formed between the hot electrode 11 and the ground electrode 21.

Further, an inlet port 15 for processing gas and inlet ports 16 and 16 for curtain gas are provided on the upper portion of the electrode holder 12.
The processing gas inlet port 15 is connected to the processing gas source 5 through a gas tube 5a. Inside the electrode holder 12, a processing gas path 12a extending from the inlet port 15 to the chamber 12b is formed. The chamber 12b is provided long in the AA direction in FIG. 1, and a slit-like nozzle hole 12c is provided on the lower side of the chamber 12b. The nozzle hole 12c faces the discharge space 50 and the electrode holder 12. Open on the lower surface of the. Further, the opening of the nozzle hole 12 c is provided at the peripheral edge of the alumina plate 13.

On the upper part of the electrode holder 12, a pair of inlet ports 16 and 16 for curtain gas are provided.
These curtain gas inlet ports 16 and 16 are connected to the curtain gas source 6 via gas tubes 6a, respectively. The gas tube 6a is branched into two in the middle and extends to the left and right inlet ports 16 and 16, respectively. Inside the electrode holder 12, curtain gas passages 12d and 12d extending from the respective inlet ports 16 and 16 to the chambers 12e and 12e are provided. These chambers 12e and 12e are long in the BB direction in FIG. 1, and slit-like nozzle holes 12f and 12f are provided below the chambers 12e and 12e. It faces the discharge space 50 and opens on the lower surface of the electrode holder 12. Further, the openings of the nozzle holes 12 f and 12 f are provided at the peripheral edge of the alumina plate 13.

The processing gas source 5 is filled with a processing gas such as N ₂ , O ₂ , or CF ₂ , and the curtain gas source 6 is filled with a curtain gas made of an inert gas such as N ₂ , for example. . When the process gas and the curtain gas are the same gas, either one of the gas sources 5 and 6 can be used as a common gas source.

Next, the alumina plates 60 and 61 that are characteristic portions of the present invention will be described with reference to FIG.
FIG. 4 is a perspective view showing the alumina plate 60 and the alumina plate 61 in FIG.

The alumina plates 60 and 61 provided on the opposing surface of the earth electrode 21 have plate shapes (L315 mm × W430 mm × t1 mm), respectively. The alumina plates 60 and 61 are provided on the alumina plate 13 provided in the upper unit 10. Are provided in parallel.
Since the alumina plates 60 and 61 and the alumina plate 13 are parallel to each other, it is possible to prevent the electric charge from being biased in the discharge space 50 when a voltage is applied, and as a result, the discharge space even under a pressure near atmospheric pressure. The occurrence of abnormal discharge in 50 can be prevented.

The alumina plate (first plate-like dielectric) 60 and the alumina plate (second plate-like dielectric) 61 are provided on the opposing surface of the ground electrode 21 in a state of being adjacent to each other.
Here, when the two alumina plates 60 and 61 are provided on the opposing surface of the earth electrode 21, for example, when only the alumina plate 60 is damaged, the earth electrode is again replaced by replacing only the damaged alumina plate 60. Since the 21 opposing surfaces can be covered, the cost for the alumina plate can be reduced as compared with the case of using one large alumina plate.

The alumina plates 60 and 61 are configured by main body portions 60a and 61a each having a rectangular parallelepiped shape, and joint portions 60b and 61b extending from side surfaces in the longitudinal direction of the main body portions 60a and 61a. The joint portions 60b and 61b extend in a direction parallel to the main surfaces of the main body portions 60a and 61a of the alumina plates 60 and 61, and the alumina plates 60 and 61 have an L-shaped cross section having a flat tenon structure. There is no.
The joint portions 60b and 61b are thinner than the main body portions 60a and 61a, and the joint portions 60b and 61b are half the thickness of the main body portions 60a and 61a so that the shapes of the joint portions 60b and 61b are equal. .

The joint portion 60b of the alumina plate 60 is connected so that the joint portion 61b of the alumina plate 61 faces downward and covers the joint portion 61b, and the joint portion 60b and the joint portion 61b are connected to each other. It is made to structure.
Also, the upper surface (main surface) of the alumina plate 60 on the hot electrode 11 side and the upper surface (main surface) of the alumina plate 61 on the hot electrode 11 side are flush with each other, and between the joint portion 60b and the joint portion 61b. There are no gaps formed.

  The joint portions 60b and 61b connecting the alumina plates 60 and 61 are extended from the side surfaces of the main body portions 60a and 61b, so that the alumina plates 60 and 61 are joined from the upper surface side through the surfaces of the joint portions 60b and 61b. The outer peripheral distance to the lower surface side of the plates 60 and 61 becomes longer. As the outer peripheral distance becomes longer, the creeping discharge generated when the voltage is applied is attenuated until the creeping discharge develops between the joint portions 60b and 61b and reaches the surface on the hot electrode 11 side. Occurrence can be prevented.

  The alumina plates 60 and 61 have equal distances L1 and L2 from the side surfaces of the main body portions 60a and 61a to the tips 60c and 61c of the joint portions 60b and 61b. Since the distances L1 and L2 are equal to each other, no gap is formed between the front ends 60c and 61c and the side surfaces of the main body portions 60a and 61a. Therefore, abnormal discharge occurs between the side surfaces of the main body portion 60a and the front end 61c. There is no fear of it occurring.

  The distances L1 and L2 from the side surfaces of the main body portions 60a and 61a to the tips 60c and 61c are 20 mm, which is 20 times the thickness (1 mm) of the main body portions 60a and 61a. Since the distances L1 and L2 are 20 times the thickness of the main body portions 60a and 61a, the lower surface side of the alumina plates 60 and 61 from the upper surface side of the alumina plates 60 and 61 through the surfaces of the joint portions 60b and 61b. The outer peripheral distance is equal to or longer than the progress distance of the creeping discharge, and the creeping discharge is attenuated before it progresses between the joint portions 60b and 61b and reaches the surface on the hot electrode 11 side, and abnormal discharge due to the creeping discharge occurs. Can be effectively prevented.

  In addition, as a manufacturing method of the joint parts 60b and 61b of the alumina plates 60 and 61, the method etc. which scrape the periphery of a plate-shaped alumina plate are mentioned, for example.

  Here, it can be confirmed by the following method that the alumina plates 60 and 61 are adjacent to each other and that the alumina plates 60 and 61 are flush with each other.

  As a method for confirming that the alumina plates 60 and 61 are adjacent to each other, for example, the alumina plates 60 and 61 are visually observed from the hot electrode 11 side, and no gap is formed between the alumina plate 60 and the alumina plate 61. A method for confirming that the boundary between the alumina plate 60 and the alumina plate 61 is a straight line.

  As a method for confirming that the alumina plates 60 and 61 are flush with each other, for example, the alumina plates 60 and 61 are visually observed from an oblique direction with respect to the surface formed by the alumina plates 60 and 61, and the alumina plate 60 Or a method for confirming that there is no shadow of the tip 61c of the alumina plate 61.

A procedure for replacing the alumina plate 61 when the alumina plate 61 is damaged will be described.
First, the undamaged alumina plate 60 is taken out from the recess 22y, and then the damaged alumina plate 61 is taken out from the recess 22y.

  Instead of the broken alumina plate 61, a new alumina plate having the same shape as the alumina plate 61 is prepared. After the damaged alumina plate 61 is taken out, a new alumina plate is placed on the recess 22y, and the periphery of the new alumina plate is aligned with the periphery of the recess 22y. At this time, the new alumina plate is provided in the recess 22y so that the joint portion of the new alumina plate is on the lower side and the joint portion of the new alumina plate is not adjacent to the periphery of the recess 22y.

After a new alumina plate is provided in the concave portion 22y, the alumina plate 60 previously taken out is put on the concave portion 22y in the joint portion of the new alumina plate. At this time, the alumina plate 60 is provided so that the joint portion 60b of the alumina plate 60 is on the upper side and the lower side of the joint portion 60b is placed on the joint portion of a new alumina plate.
The broken alumina plate 61 is replaced by the above procedure.

A procedure for performing plasma processing on the substrate W using the plasma processing apparatus M configured as described above will be described.
First, the upper unit 10 is slid in the direction of the arrow a while holding the handle 14a, and the upper surface of the lower unit 20 is exposed. Next, the base material W is placed on the alumina plates 60 and 61 of the lower unit 20, and the upper unit 10 is slid in the direction of the arrow b while holding the handle 14 a to move above the base material W. The base material W is located in the discharge space 50 between the upper unit 10 and the lower unit 20.

  After the upper unit is slid in the direction of the arrow b, the processing gas is introduced from the processing gas source 5 into the inlet port 15 through the gas tube 5a. The processing gas introduced into the inlet port 15 is made uniform in the chamber 12b through the processing gas passage 12a and blown out from the nozzle hole 12c toward the discharge space 50.

  Similar to the processing gas, curtain gas is introduced from the curtain gas source 6 to the inlet ports 16 and 16 through the gas tube 6a. The curtain gas introduced into the inlet ports 16 and 16 is made uniform in the chambers 12e and 12e through the curtain gas passages 12d and 12d, and blown out from the nozzle holes 12f and 12f toward the peripheral edges of the alumina plates 60 and 61. Is done. By blowing out the curtain gas toward the peripheral edges of the alumina plates 60 and 61, it is possible to prevent the processing gas from diffusing from the discharge space 50 to the outside.

  Then, in a state where the processing gas is supplied to the discharge space 50, the switch of the power source 1 is turned on, and application of a pulse voltage to the hot electrode 11 is started. The processing gas supplied to the discharge space 50 by the application of the pulse voltage becomes a uniform glow state plasma even under a pressure near atmospheric pressure, and the surface of the substrate W is subjected to plasma processing by the processing gas plasma.

  The used processing gas or the like used for the plasma processing is sucked from the duct 40 and exhausted by driving the vacuum pump 4.

After the plasma processing on the substrate W is completed, the supply of the processing gas and the curtain gas is stopped and the power source 1 is turned off. Then, while holding the handle 14a, the upper unit 10 is slid in the direction of arrow a to expose the upper surface of the lower unit 20 again, and the substrate W on which the plasma treatment has been performed is taken out.
The plasma treatment for the substrate W is performed through the above steps.

FIG. 5 illustrates a second embodiment of the present invention.
FIG. 5 is a perspective view to which an alumina plate using a creeping barrier is applied in the first embodiment.
In the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  The alumina plates 62 and 63 each have a plate-like body having the same shape (L315 mm × W430 mm × t1 mm). The alumina plate (first plate-like dielectric) 62 and the alumina plate (second plate-like dielectric) 63. Are adjacent to each other.

The alumina plates 62 and 63 are configured by main body portions 62a and 63a each having a rectangular parallelepiped shape, and joint portions 62b and 63b extending from the side surfaces in the longitudinal direction of the main body portions 62a and 63a. The joint portions 62b and 63b extend in a direction parallel to the main surfaces of the main body portions 62a and 63a of the alumina plates 62 and 63, and the alumina plates 62 and 63 have an L-shaped cross section having a flat tenon structure. There is no.
Further, the joint portions 62b and 63b are made thinner toward the ends 62c and 63c.

The joint portion 62b of the alumina plate 62 is connected so as to cover the joint portion 63b with the joint portion 63b of the alumina plate 63 facing down, and the joint structure 62b and the joint portion 63b are connected to each other. It is made to structure.
The upper surface (main surface) of the alumina plate 62 on the hot electrode 11 side and the upper surface (main surface) of the alumina plate 63 on the hot electrode 11 side are flush with each other.

The alumina plates 62 and 63 have the same distances L3 and L4 from the side surfaces of the main body parts 62a and 63a to the tips 62c and 63c of the joint parts 62b and 63b. The distances L3 and L4 are equal to the main body parts 62a and 63b. It is 20 mm, which is 20 times the thickness (1 mm) of 63a.

  Here, a film-like silicone rubber 70 is provided between the joint part 62b and the joint part 63b. The silicone rubber 70 is deformable and is in close contact with the joint portions 62b and 63b without forming a gap between the joint portion 60b and the joint portion 61b.

  Since the silicone rubber 70 is in close contact with the joint portions 62b and 63b, it is possible to prevent the occurrence of creeping discharge between the joint portions 62b and 63b, and to completely prevent the occurrence of abnormal discharge due to the creeping discharge. Can do. Further, by providing the silicone rubber 70 between the joint portions 62b and 63b, even if the joint portions 62b and 63b are not completely in close contact with each other due to errors in processing accuracy or attachment accuracy of the joint portions 62b and 63b, Generation of abnormal discharge due to creeping discharge can be prevented.

FIG. 6 illustrates a third embodiment of the present invention.
FIG. 6 is a perspective view in which alumina plates having different shapes are applied in the first embodiment.
In the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  The alumina plates 64 and 65 each have a plate-like body having the same shape (L315 mm × W430 mm × t1 mm). The alumina plate (first plate-like dielectric) 64 and the alumina plate (second plate-like dielectric) 65 are formed. Are adjacent to each other.

The alumina plates 64 and 65 are configured by main body portions 64a and 65a each having a rectangular parallelepiped shape, and joint portions 64b and 65b extending from side surfaces in the longitudinal direction of the main body portions 64a and 65a. The joint portions 64b and 65b are extended in a direction parallel to the main surfaces of the main body portions 64a and 65a of the alumina plates 64 and 65, and the cross-sectional shapes of the joint portions 64b and 65b are triangular.
Further, the joint portions 64b and 65b are made thinner toward the tips 64c and 65c.

The joint portion 64b of the alumina plate 64 is connected so as to cover and overlap the joint portion 65b with the joint portion 65b of the alumina plate 65 facing down, and the connection structure thereof is a wing joint structure. Here, the shapes of the joint portions 64b and 65b are equal to each other, and no gap is formed between the joint portion 64b and the joint portion 65b.
The upper surface (main surface) of the alumina plate 64 on the hot electrode 11 side and the upper surface (main surface) of the alumina plate 65 on the hot electrode 11 side are flush with each other.

  The joint portion 64b of the alumina plate 64 is connected to the joint portion 65b of the alumina plate 65 so as to cover the joint portion 65b with the joint portion 65b of the alumina plate 65 facing down, and the connection structure thereof is a wing joint structure. Has been made. Here, the shapes of the joint portions 64b and 65b are equal to each other, and no gap is formed between the joint portion 64b and the joint portion 65b.

  The distances L5 and L6 from the side surfaces of the main body portions 64a and 65a to the tips 64c and 65c of the joint portions 64b and 65b are 10 mm, which is 10 times the thickness (1 mm) of the main body portions 64a and 65a. By making this distance 10 times the thickness of the main body portions 64a and 65a, the outer periphery from the upper surface side of the alumina plates 64 and 65 to the lower surface side of the alumina plates 64 and 65 through the surfaces of the joint portions 64b and 65b. Since the distance is equal to or longer than the progress distance of the creeping discharge, the occurrence of abnormal discharge due to the creeping discharge can be prevented.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, the connection structure of each joint portion in the first plate-like dielectric and the second plate-like dielectric is not limited to the phase-joint structure or the wing-joint structure. It may be a structure or the like.
As a method for assembling the lower unit, two alumina plates with joint portions connected in advance may be provided in the recess 22y.

The number of plate dielectrics used in the plasma processing apparatus of the present invention is not limited to two, and may be three or more. When three or more plate dielectrics are used, it is only necessary that a joint portion is provided on the side where the plate dielectrics are adjacent to each other, and two or more joint portions are provided on one plate dielectric. May be.
The replacement method of the plate dielectric when the plate dielectric is damaged is not limited to the above method, and the damaged plate dielectric may be removed first.

It is a perspective view of the plasma processing apparatus of this invention. It is sectional drawing of the plasma processing apparatus which follows the AA line of FIG. It is sectional drawing of the plasma processing apparatus which follows the BB line of FIG. It is a perspective view which shows the 1st plate-like dielectric material in FIG. 2, and the 2nd plate-like dielectric material. It is a perspective view which shows the 1st plate-shaped dielectric material and 2nd plate-shaped dielectric material in 2nd Embodiment. It is a perspective view which shows the 1st plate-shaped dielectric material and 2nd plate-shaped dielectric material in 3rd Embodiment.

Explanation of symbols

M Plasma processing apparatus W Substrate 1 Power source 1a Power supply line 2a Grounding wire 3 Base 4 Vacuum pump 5 Process gas source 6 Curtain gas source 10 Upper unit 20 Lower unit 11 Hot electrode 21 Earth electrodes 12, 22 Electrode holder 50 Discharge space 13 60, 61, 62, 63, 64, 65 Alumina plates 60a, 61a, 62a, 63a, 64a, 65a, body portions 60b, 61b, 62b, 63b, 64b, 65b, joint portions 60c, 61c, 62c, 63c, 64c, 65c, tip 70 Silicone rubber

Claims (3)

Having a pair of electrodes facing each other,
In a plasma processing apparatus for performing plasma processing on a target object using plasma generated between the pair of electrodes,
A plasma processing apparatus, wherein a first plate-like dielectric and a second plate-like dielectric adjacent to each other are provided on an opposing surface of at least one of the pair of electrodes. The first plate-like dielectric body and the second plate-like dielectric body include a main body portion that forms a plate-like body, and a joint portion that extends from a side surface of the main body portion and is thinner than the main body portion. And
The joint portion of the first plate-like dielectric is connected to the joint portion of the second plate-like dielectric so that the main surfaces of the main body are substantially flush with each other. The plasma processing apparatus according to claim 1. 4. The plasma processing apparatus according to claim 2, wherein a creeping barrier is provided between the joint portion of the first plate dielectric and the joint portion of the second plate dielectric. 5. .

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