JP2009228054A - Plasma electrode and plasma chemical vapor deposition system - Google Patents

Abstract

A plasma electrode capable of generating uniform plasma while suppressing abnormal discharge is provided.
A substrate electrode on which a substrate on which a thin film is deposited by a plasma reaction is placed, and a first main surface 6 and a first main surface facing the substrate electrode across the plasma space for generating plasma and facing the plasma space. A high-frequency electrode 10 having a plurality of gas blowing portions penetrating from the first main surface to the second main surface is defined by defining a second main surface 8 opposite to the surface 6. Among the plurality of gas blowing portions of the high-frequency electrode 10, at least a gas blowing portion provided on the outer peripheral portion has the first opening 2 and the second opening 4 connected to the first opening 2, and the first The opening width of the opening 2 is smaller than that of the second opening 4, and the length of the first opening 2 measured in the penetrating direction is 1 mm or less.
[Selection] Figure 3

Description

  The present invention relates to a parallel plate type plasma electrode and a plasma enhanced chemical vapor deposition apparatus.

A plasma electrode of a parallel plate type plasma chemical vapor deposition (CVD) apparatus includes a substrate electrode and a high-frequency electrode arranged to face the substrate electrode. A substrate to be processed such as a semiconductor substrate is placed on the upper surface of the substrate electrode. The high-frequency electrode is provided with a plurality of gas blowing portions for blowing process gas toward the substrate to be processed. When a silicon nitride (Si ₃ N ₄ ) film used for an antireflection film of a solar cell or the like in which high frequency power is supplied between the substrate electrode and the high frequency electrode is formed with a plasma CVD apparatus, monosilane (SiH ₄ ) is used as a process gas. Nitrogen (N ₂ ), ammonia (NH ₃ ), etc. are used. Usually, the gas blowing portion is a through-hole having a constant diameter of about 0.3 mm to 2 mm on the entire surface of the high-frequency electrode.

  When high-frequency power is supplied to the high-frequency electrodes while the process gas is blown from the gas blowing portion toward the substrate, substantially uniform plasma is generated in the space between the parallel plate type plasma electrodes. Since the generated plasma promotes chemical reaction such as dissociation and excitation with respect to the process gas, the film can be formed on the substrate even when the substrate temperature is lower than that of thermal CVD (200 ° C. to 600 ° C.).

  In the parallel plate type plasma CVD apparatus, in order to improve the film forming speed, it is usually performed to increase the high frequency power applied to the plasma electrode. In this case, when the input power exceeds a certain threshold value, discharge due to the so-called hollow cathode effect occurs. In order to obtain a high deposition rate by actively utilizing the hollow cathode effect, a plurality of cross-sectional shapes are curved or conical so that the diameter of the through hole of the gas blowing portion is increased on the surface side in contact with the plasma. A hollow high-frequency electrode formed by arranging the depressions at equal intervals has been proposed (see Patent Documents 1 and 2).

  When the input power exceeds the threshold in a normal plasma electrode, the plasma emission intensity locally increased in the through-hole in a specific area on the surface of the high-frequency electrode from the normal discharge state where uniform plasma was generated. Transition to an abnormal discharge state due to the cathode effect. When abnormal discharge occurs in the specific region, high frequency power is discontinuously consumed in the specific region as compared with the region of the high frequency electrode other than the specific region. In addition, a reaction that contributes to film formation in a specific region is promoted. As a result, there is a problem that the film formation distribution on the substrate becomes extremely non-uniform.

Further, when an insulating film such as a Si ₃ N ₄ film is formed, an insulating deposit adheres to the surface of the plasma electrode in contact with the plasma. Electrons accumulate in the deposit on the plasma electrode and are negatively charged. Each time the film forming process is repeated, the thickness of the deposit attached to the surface of the high-frequency electrode increases, and the deposit also adheres to the inner wall of the through hole of the gas blowing portion. The deposit on the inner wall of the through hole becomes negatively charged, and the frequency of receiving ion bombardment due to ion incidence from plasma increases. In general, the secondary electron emission coefficient of the insulator is high, and a large amount of secondary electrons are generated from the deposit by ion bombardment, and the ionization of the process gas near the axis of the through hole is promoted. In this way, ion bombardment on the inner wall of the through hole to which the deposit is attached increases at an accelerated rate, and finally a catastrophic abnormal discharge occurs in the through hole in a specific region.

In order to suppress abnormal discharge due to the hollow cathode effect, the thickness of the high-frequency electrode may be reduced so that ionization of the process gas in the gas blowing portion is not promoted. However, in plasma CVD, the temperature of the structure around the plasma is about 200 ° C. to 600 ° C. in order to accelerate the film formation reaction on the substrate and reduce the adhesion of deposits to the structure around the plasma including the plasma electrode. It is kept at a high temperature. Therefore, when the high frequency electrode is thinned, the high frequency electrode is significantly deformed due to thermal strain. As a result, there is a problem that non-uniform plasma is generated and the film formation distribution on the substrate becomes non-uniform.
Japanese Patent Publication No. 1-139771 JP 2002-27459 A

  Conventionally, measures have been taken in the direction of reducing the diameter of the through-holes for the gas blowout in order to increase the threshold value of the high-frequency power that shifts from the normal discharge state to the abnormal discharge state. However, once the high frequency power exceeds the threshold value and shifts to an abnormal discharge state, an insulating deposit rapidly adheres to the inner wall of the through hole that has caused the abnormal discharge. For this reason, it is difficult to maintain a normal discharge state unless the deposit adhered off-line is removed.

  In view of the above problems, an object of the present invention is to provide a plasma electrode and a plasma CVD apparatus that can generate a uniform plasma while suppressing abnormal discharge.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided: (a) a substrate electrode on which a substrate on which a thin film is deposited by plasma reaction is placed; and (b) a substrate sandwiching a plasma space for generating plasma. A plurality of gas blowing portions that define both sides by a first main surface facing the electrode and facing the plasma space and a second main surface opposite to the first main surface and penetrating from the first main surface to the second main surface (C) a second opening in which a gas blowing portion provided at least on the outer periphery of the high-frequency electrode among the plurality of gas blowing portions is connected to the first opening and the first opening. The gist of the present invention is that the first electrode has a width smaller than that of the second opening, and the length of the first opening measured in the penetrating direction is 1 mm or less.

  According to a second aspect of the present invention, there is provided a plasma chemical vapor phase comprising: (a) a processing chamber for performing a plasma chemical vapor deposition process; and (b) a plasma electrode according to the first aspect of the present invention disposed in the processing chamber. The gist is that it is a deposition apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the plasma electrode and plasma CVD apparatus which can suppress the abnormal discharge and can produce | generate uniform plasma can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the configuration of the apparatus and system is different from the actual one. Therefore, a specific configuration should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different structures and the like are included between the drawings.

  The following embodiments of the present invention exemplify apparatuses and methods for embodying the technical idea of the present invention. The technical idea of the present invention is based on the material and shape of component parts. The structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

(First embodiment)
As shown in FIG. 1, the plasma CVD apparatus according to the first embodiment of the present invention includes a processing chamber 30 for performing plasma CVD processing, plasma electrodes (10, 12) disposed in the processing chamber 30, and the like. Prepare. The plasma electrodes (10, 12) include a substrate electrode 12 and a high-frequency electrode 10 facing the substrate electrode 12. A plasma space in which plasma 14 is generated is sandwiched between the substrate electrode 12 and the high-frequency electrode 10. A substrate 20 on which a thin film is deposited by the reaction of plasma 14 is placed on the surface of the substrate electrode 12. The high-frequency electrode 10 is provided in a shower head 42 to which process gas is supplied through a gas pipe 40. A diffusion plate may be provided between the high frequency electrode 10 and the gas pipe 40 in order to supply the process gas uniformly to the entire surface of the high frequency electrode 10. The processing chamber 30 is evacuated by a vacuum pump (not shown) connected to the exhaust pipe 34. The substrate electrode 12 is grounded through the processing chamber 30. A high frequency power source 36 for plasma generation is connected to the high frequency electrode 10.

  The high-frequency electrode 10 has a shape based on a parallel plate in which both surfaces are defined by a first main surface 6 facing the plasma space and a second main surface 8 opposite to the first main surface 6. Since the first main surface 6 faces the plasma space so as to face the substrate 20 on the substrate electrode 12 across the plasma space, the second main surface 8 is located on the process gas supply side.

  As shown in FIGS. 2 and 3, the high-frequency electrode 10 has a rectangular shape and a thickness Tt. Note that the shape of the high-frequency electrode 10 is not limited to a rectangular shape, and may be a circular shape, a polygonal shape, or the like. The high-frequency electrode 10 has a plurality of gas blowing portions (2, 4) penetrating from the first main surface 6 to the second main surface 8. The gas blowing portions (2, 4) are provided on the first main surface 6 side and the second opening portion provided on the second main surface 8 side and connected to the first opening 2. 4.

  Both the first and second openings 2 and 4 are circular holes having a rectangular cross-section cut along the direction through which the gas blowing parts (2 and 4) pass, and their axial centers are substantially collinear. The diameter (opening width) Wa of the first opening 2 is smaller than the diameter (opening width) Wb of the second opening 4. Moreover, the length of the 1st opening part 2 measured in the direction which the gas blowing part (2, 4) penetrates is Ta.

  The high frequency electrode 10 is made of metal. The first and second openings 2 and 4 are formed by machining, for example.

For example, when a Si ₃ N ₄ film is deposited by plasma CVD, a gas such as SiH ₄ , N ₂ , or NH ₃ is used as a process gas. The process gas is supplied to the shower head 42 from the gas pipe 40 shown in FIG. The process gas is supplied from the second main surface 8 of the high-frequency electrode 10 toward the first main surface 6 through the gas blowing portions (2, 4) into the plasma space between the high-frequency electrode 10 and the substrate 20. While heating the substrate 20 and the high-frequency electrode 10 to a predetermined temperature of about 200 ° C. to 600 ° C., high-frequency power is supplied from the high-frequency power source 36 to the high-frequency electrode 10 to generate plasma 14. In this way, a Si ₃ N ₄ film is deposited on the substrate 20. At the same time, insulating deposits also adhere to the surface of the high-frequency electrode 10.

  The thickness Tt of the high-frequency electrode 10 is preferably in the range of 3 mm to 10 mm in order to suppress the influence of deformation or the like due to thermal strain. In order to supply the process gas uniformly into the plasma, the diameter Wa of the first opening 2 is desirably 2 mm or less. In order to avoid clogging of the first opening 2 due to deposits adhering to the inner wall of the first opening 2 during CVD, the diameter of the first opening 2 is desirably 0.3 mm or more. In order to prevent discontinuous abnormal discharge, the diameter Wb of the second opening 4 is desirably 5 mm or more. In order to uniformly supply process gas into the plasma from the gas blowing portions (2, 4), the diameter of the second opening 4 is desirably 20 mm or less. Furthermore, the length Ta of the first opening 2 is desirably 1 mm or less. This is because if the length Ta of the first opening 2 exceeds 1 mm, the abnormal discharge generated in the first opening 2 is easily sustained and leads to a catastrophic abnormal discharge.

  As shown in FIG. 4, in the conventional high-frequency electrode 110, a through hole 102 that penetrates from the first main surface 106 to the second main surface 108 is provided as a gas blowing portion. The through hole 102 has an inner wall 107 perpendicular to the first and second main surfaces 106 and 108. As shown in FIG. 5, the process gas is supplied from the second main surface 108 side, and plasma 14 is generated between the first main surface 106 and the substrate (not shown). When plasma CVD is performed for a long time, an insulating deposit 120 accumulates on the first main surface 106 that contacts the plasma of the high-frequency electrode 110 and on the inner wall 107 of the through hole 102.

  A self-bias voltage is generated by the generated plasma 14 on the first main surface 106 side of the high-frequency electrode 110. Since the self-bias voltage is blocked and held by the impedance matching unit included in the high-frequency power source, the charged state of the deposit 120 attached on the first main surface 106 of the high-frequency electrode 110 has little influence on the plasma 14. Further, even if secondary electron emission from the deposit 120 increases due to ion bombardment, the discharge region between the high-frequency electrode 110 and the substrate is continuous, so that the plasma 14 due to self-adjustment and stable discharge is maintained.

On the other hand, when the deposit 120 is accumulated on the inner wall 107 of the through hole 102, the surface of the deposit 120 is negatively charged, and the frequency of ion bombardment is increased. Further, the deposit 120 is an insulating material and has a high secondary electron emission coefficient. Further, the thickness of the high-frequency electrode 110 is set to a range of 3 mm to 10 mm in order to prevent deformation due to thermal strain. Thus, since the region surrounded by the inner wall 107 of the through hole 102 is sufficiently thick, a large amount of secondary electrons are emitted by ion bombardment. The emitted secondary electrons promote ionization of the process gas near the axis of the through hole 102. Therefore, when a discharge occurs in the through hole 102, the ion I ⁺ and the electron e ⁻ reciprocate between the region near the axial center of the through hole 102 and the surface of the deposit 120 attached to the inner wall 107 to promote ionization. Further increase. When the diameter of the through hole 102 is 2 mm or less, the discharge region generated in the through hole 102 is discontinuous with the plasma 14 generated on the entire surface of the first main surface 106. As a result, the effect of increasing the secondary electron emission is synergized with the hollow cathode effect, and a catastrophic abnormal discharge 114 is generated in the normal discharge region of the plasma 14 and the inner region of the discontinuous through hole 102.

  In the high-frequency electrode 10 according to the first embodiment, the length Ta of the first opening 2 provided on the first main surface 6 side in contact with the plasma 14 is 1 mm or less. Moreover, the diameter Wb of the 2nd opening part 4 is the range of 5 mm-20 mm. Therefore, even if the deposit attached to the inner wall of the first opening 2 is subjected to ion bombardment, the emitted secondary electrons diffuse into the plasma 14 or the second opening 4 side. Thus, since the area | region which accelerates | stimulates ionization in the 1st opening part 2 is inadequate, an abnormal discharge state cannot be maintained. Further, the thickness Tt of the high-frequency electrode 10 can be increased to a range of 3 mm to 10 mm simply by setting the length Ta of the first opening 2 to 1 mm or less in order to suppress abnormal discharge. Therefore, even if the high-frequency electrode 10 is heated, deformation due to thermal strain or the like can be prevented, and uniform plasma 14 can be generated.

  In the above-described high-frequency electrode 10, the first and second openings 2, 4 both have a rectangular cross section cut along the direction through which the gas blowing portions (2, 4) pass. However, as shown in FIG. 6, the cross section of the second opening 4 a cut along the direction through which the gas blowing portions (2, 4 a) pass is the same as the first opening 2 at the position in contact with the first opening 2. It is good also as a taper shape which is the same diameter and a diameter spreads as it leaves | separates from the 1st opening part 2 and goes to the 2nd main surface 8. As shown in FIG. Further, as shown in FIG. 7, both the first and second openings 2, 4a may be tapered. In this case, the 1st opening part 2 becomes a taper-shaped part whose diameter is 2 mm or less.

  As shown in FIGS. 8 to 10, the second openings 4 </ b> A and 4 </ b> B may be formed by a plurality of grooves provided along the direction parallel to the first and second main surfaces and intersecting each other. . The first opening 2 is formed at the intersection of the second openings 4A and 4B. Furthermore, as shown in FIGS. 11 and 21, the second opening 4A may be formed by a plurality of grooves arranged in parallel along a direction parallel to the first and second main surfaces. The first opening 2 is formed on the bottom surface of the groove.

  Further, when no special means for maintaining the temperature uniformity of the high-frequency electrode is applied, generally the temperature of the outer peripheral region of the high-frequency electrode tends to be lower than that of the central region. For this reason, the deposit adheres rapidly in the outer peripheral region of the high-frequency electrode. As a result, abnormal discharge is likely to occur in the outer peripheral region of the high-frequency electrode. Therefore, as shown in FIG. 13, gas blowing portions (2, 4) having first and second openings 2, 4 are provided in one row and one column of the outer peripheral portion of the high-frequency electrode 10, and the first opening is formed in the central region. You may provide the gas blowing part 2a which consists of a through-hole with the same diameter as the part 2. FIG. Further, as shown in FIG. 14, grooves provided in one row and one column in the outer peripheral portion of the high-frequency electrode 10 may be used as the second openings 4A and 4B. By providing the second openings 4, 4 </ b> A, 4 </ b> B on the outer periphery of the high-frequency electrode 10, abnormal discharge at the outer periphery can be prevented. By applying such a structure, machining can be simplified and manufacturing costs can be reduced. In addition, you may provide the 2nd opening part of an outer peripheral part in several rows and several columns.

(Second Embodiment)
As shown in FIGS. 15 and 16, the high-frequency electrode 10 according to the second embodiment of the present invention has a rectangular shape and a thickness Tt. The high-frequency electrode 10 has a plurality of gas blowing portions (2, 4) penetrating from the first main surface 6 to the second main surface 8. The gas blowing portions (2, 4) are provided on the second main surface 8 side and the second opening portion provided on the first main surface 6 side and connected to the first opening portion 2. 4.

  Both the first and second openings 2 and 4 are circular holes having a rectangular cross-section cut along the direction through which the gas blowing parts (2 and 4) pass, and their axial centers are substantially collinear. The diameter (opening width) Wa of the first opening 2 is smaller than the diameter (opening width) Wb of the second opening 4. Moreover, the length of the 1st opening part 2 measured in the direction which the gas blowing part (2, 4) penetrates is Ta.

  The thickness Tt of the high-frequency electrode 10 is preferably in the range of 3 mm to 10 mm in order to suppress the influence of deformation or the like due to thermal strain. In order to supply the process gas uniformly into the plasma, the diameter Wa of the first opening 2 is desirably 2 mm or less. In order to avoid clogging of the first opening 2 due to deposits adhering to the inner wall of the first opening 2 during CVD, the diameter of the first opening 2 is desirably 0.3 mm or more. Moreover, in order to prevent a discontinuous abnormal discharge, the diameter Wb of the 2nd opening part 4 has the desirable range of 5-20 mm. If the diameter Wb of the second opening 4 is in the range of 5 mm to 20 mm, the plasma intensity increases in the second opening 4 due to the hollow cathode effect, but a discontinuous discharge state occurs in the second opening 4. Can be suppressed. Furthermore, the length Ta of the first opening 2 is desirably 1 mm or less. This is because if the length Ta of the first opening 2 exceeds 1 mm, the abnormal discharge generated in the first opening 2 is easily sustained and leads to a catastrophic abnormal discharge.

  The second embodiment is different from the first embodiment in that the first opening 2 is arranged on the second main surface 8 side and the second opening 4 is arranged on the first main surface 6 side. . Other configurations are the same as those of the first embodiment, and thus redundant description is omitted.

  In the second embodiment, the second opening 4 is in contact with the plasma 14 generated between the high-frequency electrode 10 and the substrate 20 shown in FIG. The diameter Wb of the second opening 4 is as large as 5 mm to 20 mm, and the discharge generated in the second opening 4 due to the hollow cathode effect is connected to the plasma 14. Thus, in the second opening 4, a discontinuous abnormal discharge isolated from the plasma 14 does not occur. The length Ta of the first opening 2 is 1 mm or less. Therefore, since the area | region which accelerates | stimulates ionization in the 1st opening part 2 is inadequate, an abnormal discharge state cannot be maintained. As described above, in the second embodiment, the abnormal discharge in the gas blowing portions (2, 4) can be suppressed, and the plasma is uniform and high in plasma intensity between the high-frequency electrode 10 and the substrate 20. Can be generated. As a result, the deposition rate of plasma CVD can be increased.

  In the above-described high-frequency electrode 10, the first and second openings 2, 4 both have a rectangular cross section cut along the penetration direction of the gas blowing portions (2, 4). However, as shown in FIG. 17, the cross section of the second opening 4 a cut along the direction through which the gas blowing portions (2, 4 a) pass is the same as the first opening 2 at a position in contact with the first opening 2. It is good also as a taper shape which is the same diameter and the diameter expanded toward the 1st main surface 6 from the 1st opening part 2. As shown in FIG. Further, both the first and second openings 2, 4a may be tapered. In this case, the 1st opening part 2 becomes a taper-shaped part whose diameter is 2 mm or less.

  Further, as shown in FIG. 18, the second openings 4A and 4B may be formed by a plurality of grooves intersecting each other. The first opening 2 is formed at the intersection of the second openings 4A and 4B. Further, as shown in FIG. 19, the second opening 4A may be formed by a plurality of grooves arranged in parallel. The first opening 2 is formed on the bottom surface of the groove.

  Further, as shown in FIG. 20, gas blowing portions (2, 4) having first and second openings 2, 4 are provided in one row and one column of the outer peripheral portion of the high-frequency electrode 10 where abnormal discharge is likely to occur, The region may be provided with a gas blowing portion 2a formed of a through hole having the same diameter as that of the first opening 2. Further, as shown in FIG. 21, grooves provided in one row and one column in the outer peripheral portion of the high-frequency electrode 10 may be used as the second openings 4A and 4B. By providing the second openings 4, 4 </ b> A, 4 </ b> B on the outer periphery of the high-frequency electrode 10, abnormal discharge at the outer periphery can be prevented. By applying such a structure, machining can be simplified and manufacturing costs can be reduced. In addition, you may provide the 2nd opening part of an outer peripheral part in several rows and several columns.

(Other embodiments)
As mentioned above, although this invention was described by embodiment of this invention, it should not be understood that the statement and drawing which make a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

  In the description of the first and second embodiments of the present invention, the first opening 2 is provided on the first or second main surface 6, 8 side. However, as shown in FIG. 22, the first openings sandwiched between the second openings 4 on both sides are provided with the second openings 4 having a rectangular cross section on both sides of the first and second main surfaces 6, 8. Part 2 may be provided. Further, as shown in FIG. 23, the first opening is provided with the second opening 4a having a tapered cross section on both sides of the first and second main surfaces 6 and 8, and sandwiched between the second openings 4a on both sides. Part 2 may be provided. In addition, it is good also considering the cross section of one 2nd opening part on both sides of a 1st opening part as a rectangular shape, and making the other cross section into a taper shape. The first opening 2 may be tapered.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

It is the schematic which shows an example of a structure of the plasma CVD apparatus which concerns on the 1st Embodiment of this invention. It is a top view which shows an example of the high frequency electrode of the plasma electrode which concerns on the 1st Embodiment of this invention. It is the schematic which shows the cross section along the AA line of the high frequency electrode shown in FIG. It is sectional drawing which shows an example of the conventional high frequency electrode. It is the schematic explaining an example of the abnormal discharge generate | occur | produced with the conventional high frequency electrode. It is a top view which shows the other example of the high frequency electrode which concerns on the 1st Embodiment of this invention. It is a top view which shows the other example of the high frequency electrode which concerns on the 1st Embodiment of this invention. It is a top view which shows the other example of the high frequency electrode which concerns on the 1st Embodiment of this invention. It is the schematic which shows the cross section along the BB line of the high frequency electrode shown in FIG. It is the schematic which shows the cross section along CC line of the high frequency electrode shown in FIG. It is sectional drawing which shows the other example of the high frequency electrode which concerns on the 1st Embodiment of this invention. It is the schematic which shows the cross section along the DD line | wire of the high frequency electrode shown in FIG. It is a top view which shows the other example of the high frequency electrode which concerns on the 1st Embodiment of this invention. It is a top view which shows the other example of the high frequency electrode which concerns on the 1st Embodiment of this invention. It is a top view which shows an example of the high frequency electrode which concerns on the 2nd Embodiment of this invention. It is the schematic which shows the cross section along the EE line | wire of the high frequency electrode shown in FIG. It is sectional drawing which shows the other example of the high frequency electrode which concerns on the 2nd Embodiment of this invention. It is a top view which shows the other example of the high frequency electrode which concerns on the 2nd Embodiment of this invention. It is a top view which shows the other example of the high frequency electrode which concerns on the 2nd Embodiment of this invention. It is a top view which shows the other example of the high frequency electrode which concerns on the 2nd Embodiment of this invention. It is a top view which shows the other example of the high frequency electrode which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows an example of the high frequency electrode which concerns on other embodiment of this invention. It is sectional drawing which shows the other example of the high frequency electrode which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... 1st opening part 4 ... 2nd opening part 6 ... 1st main surface 8 ... 2nd main surface 10 ... High frequency electrode 12 ... Substrate electrode 14 ... Plasma 20 ... Substrate 30 ... Processing chamber

Claims (10)

A substrate electrode on which a substrate on which a thin film is deposited by a plasma reaction is placed;
Both surfaces are defined by a first main surface facing the substrate electrode across a plasma space for generating the plasma, and a second main surface opposite to the first main surface, the first main surface facing the plasma space, A high-frequency electrode having a plurality of gas blowing portions penetrating from the main surface to the second main surface,
Among the plurality of gas blowing portions, at least a gas blowing portion provided on an outer peripheral portion of the high-frequency electrode has a first opening and a second opening connected to the first opening, and the first The plasma electrode, wherein an opening width of the opening is smaller than that of the second opening, and a length of the first opening measured in the penetrating direction is 1 mm or less.   The plasma electrode according to claim 1, wherein the first opening is provided on the first main surface side.   The plasma electrode according to claim 1, wherein the first opening is provided on the second main surface side.   4. The plasma electrode according to claim 1, wherein all of the plurality of gas blowing portions have the first and second openings. 5.   Among the plurality of gas blowing portions, a gas blowing portion provided in a central region of the high-frequency electrode penetrates from the first main surface to the second main surface with the same opening width as the first opening. The plasma electrode according to claim 1, wherein the plasma electrode is characterized in that   6. The plasma electrode according to claim 1, wherein a cross-sectional shape of each of the first and second openings is rectangular in a cross section cut along the penetrating direction.   The cross-sectional shape of the second opening is the same as the first opening at a position in contact with the first opening in a cross section cut along the penetrating direction, and is away from the first opening. The plasma electrode according to claim 1, wherein the opening width increases in a taper shape.   The second opening is a plurality of grooves arranged in parallel along a direction parallel to the first and second main surfaces, and the first opening is formed on the bottom surface of the plurality of grooves. The plasma electrode according to any one of claims 1 to 5.   The second opening is a plurality of grooves provided along a direction parallel to the first and second main surfaces and intersecting each other, and the first opening is formed at an intersection of the plurality of grooves. The plasma electrode according to any one of claims 1 to 5, wherein: A processing chamber for performing plasma enhanced chemical vapor deposition,
A plasma chemical vapor deposition apparatus comprising: the plasma electrode according to claim 1 disposed in the processing chamber.

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