JP2005166869A - Dry etching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dry etching device provided with a gas blowout plate for uniforming the flow rate of a reaction gas supplied to a wafer by preventing the adhesion of a reaction product to a blowout hole, and reducing exchange frequency. <P>SOLUTION: The gas blowout plate 21 used for the dry etching device comprises carbon of 3-20 mm of a thickness t, and is provided with a great number of the blowout holes 22 on the whole face. The blowout hole 22 is composed of a large hole 23 provided at the introduction side of the reaction gas, and a small hole 24 provided at a jetting side. The hole diameter d1 of the large hole 23 is 0.6-6.0 mm, and the hole diameter d2 of the small hole 24 is 0.3-3.0 mm. The hole diameter d1 of the large hole 23 is two times or larger than the hole diameter d2 of the small hole 24. Control such as the flow rate and pressure of the reaction gas is facilitated by making the hole diameters d1 and d2 of the large hole 23 and the small hole 24 in this range, and the reaction gas of the stable flow rate can be supplied. The depth t1 of the large hole 23 is formed shallower than the depth t2 of the small hole 24, and the depth t1 of a desirable large hole 23 is 0.5-1.0 mm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dry etching apparatus that etches a semiconductor wafer (hereinafter referred to as a wafer) using a reactive gas plasma in a vacuum processing chamber, and more particularly, includes a gas blowing plate for introducing a reactive gas into the processing chamber. The present invention relates to a dry etching apparatus.

  In the manufacturing process of a semiconductor element, a dry etching apparatus using plasma of an etching gas is used to remove a predetermined film formed on the surface of a wafer. The principle of this apparatus is that etching is performed by activating a reactive gas to ions or radicals in a plasma atmosphere, reacting with a predetermined film, and vaporizing a reaction product.

  Such a technique is disclosed in, for example, Japanese Patent Laid-Open No. 5-55172 (Patent Document 1). FIG. 4 is a cross-sectional view of a conventional dry etching apparatus. In the conventional dry etching apparatus 51 shown in FIG. 4, an upper electrode 53 and a lower electrode 54 are disposed in a vacuum chamber 52 so as to face each other, and a wafer 55 as an object to be etched is placed on the lower electrode 54. Yes. The upper electrode 53 is hollow, and the reaction gas is supplied from the gas supply pipe 56 therein, and is connected to the ground and held at zero potential. A gas supply source 59 is connected to the gas supply pipe 56 via a gas supply valve 57 and a gas flow rate adjusting unit 58. In addition, a high frequency power supply 61 is electrically connected to the lower electrode 54 via a matching unit 60. Further, a vacuum pump 64 such as a turbomolecular pump, a mechanical booster pump, or a rotary pump is connected to the gas exhaust pipe 62 below the vacuum chamber 52 through a pressure control valve 63 in order to exhaust the reaction gas. . Further, inside the upper electrode 53, a gas blowing plate 65 for supplying a reaction gas into the vacuum chamber 52 and a ring-shaped anode cover 66 for fixing the gas blowing plate 65 to the upper electrode 53 are attached. . A large number of blowout holes 67 having the same hole diameter are formed in the gas blowout plate 65.

  In the operation of the conventional dry etching apparatus 51, first, the wafer 55 is placed on the lower electrode 54 in the vacuum chamber 52. Next, the pressure control valve 63 is opened and the vacuum pump 64 is operated to evacuate the vacuum chamber 52. When the pressure in the vacuum chamber 52 reaches a predetermined pressure, the gas supply valve 57 is opened, and a predetermined flow rate of reaction gas is supplied from the gas supply source 59 to the vacuum chamber 52 by the gas flow rate adjustment unit 58. Subsequently, high-frequency power is supplied from the high-frequency power source 61 to the lower electrode 54 while controlling the impedance by the matching unit 60, a reactive gas plasma 68 is generated, and the wafer 55 is etched by the impact energy of the ions.

  Further, in the above-described prior art, another dry etching apparatus has been proposed in order to make the flow rate of the reaction gas supplied into the vacuum chamber 52 more uniform. FIG. 5 is a cross-sectional view of the dry etching apparatus. A dry etching apparatus 71 shown in FIG. 5 includes an upper electrode 53, three gas supply pipes 72a to 72c, three gas supply valves 73a to 73c, and a gas flow rate adjusting unit that controls the supply valves 73a to 73c. 74 and a gas supply source 75 are newly provided. Further, the hollow portion of the upper electrode 53 can supply the reaction gas independently from the three gas supply pipes 72a to 72c by the partition walls 76a and 76b. In the operation of the dry etching apparatus 71, a gas concentration distribution between the upper electrode 53 and the lower electrode 54 is measured by a gas sensor (not shown) provided in the vacuum chamber 52. And each gas supply valve 73a-73c is adjusted by the gas flow volume adjustment part 74 so that gas concentration distribution may become uniform, and the etching rate in the wafer 55 surface is made uniform.

  However, in the conventional dry etching apparatuses 51 and 71, since the diameters of the numerous blow holes 67 provided in the gas blow plate 65 are large, a part of the plasma 68 easily goes around during the etching process of the wafer 55, and the blow holes are formed. The reaction product adhered to the inner wall of 67 and the gas introduction side surface. Since this reaction product is charged up and abnormal discharge is likely to occur, it is necessary to clean the gas blowing plate 65 frequently.

  In this regard, Japanese Patent Application Laid-Open No. 2001-223204 (Patent Document 2) discloses a technique for reducing the number of cleanings by preventing the plasma from flowing into the blowing holes of the gas blowing plate. 6 (a) and 6 (b) are cross-sectional views of the disclosed gas blowing plate.

In the gas outlet plate 81 shown in FIG. 6A, a tapered outlet hole 82 having a maximum diameter d1 on the gas introduction side and a minimum diameter d2 on the gas outlet side is formed at a distance L between the centers of the adjacent outlet holes 82. On the other hand, it is formed so that d2 <d1 <L / 2. In addition, the gas outlet plate 83 shown in FIG. 6B is formed with a cylindrical outlet hole 84 having a maximum diameter d1 on the gas introduction side and a minimum diameter d2 on the gas injection side so as to satisfy the same relationship. ing. By providing such blowing holes 82 and 84, the reaction gas is jetted at a high pressure from the introduction side to the jetting side, so that the plasma in the vacuum chamber is suppressed from flowing around the blowing holes 82 and 84. As a result, it is possible to prevent the reaction product from adhering to the inner walls of the blowing holes 82 and 84 and the gas introduction side surface, and the number of cleanings of the gas blowing plates 81 and 83 can be reduced.
JP-A-5-55172 (pages 2 and 3, paragraphs 0002 to 0011, FIG. 3) JP 2001-223204 A (pages 3 and 4, paragraphs 0018 to 0028, FIGS. 1 and 2)

  However, the above-described prior art has the following problems. The gas blowing plates 81 and 83 shown in FIGS. 6A and 6B are etched in the same manner as the wafer to be processed by being exposed to plasma. This etching proceeds from the gas ejection side of the lower surface of the gas blowing plates 81 and 83 exposed to the plasma, and the thickness gradually decreases. When the gas blowing plate 81 shown in FIG. 6A is etched, the hole diameter of the tapered blowing hole 82 gradually increases from the minimum diameter d2, so that the flow rate of the reaction gas passing therethrough increases gradually, and the etching rate of the wafer is increased. Fluctuates. In addition, since the gas blowing plate 83 shown in FIG. 6B has a depth of the maximum diameter d1 is deep and is substantially the same depth as the minimum diameter d2, the reaction gas stays in this portion. As a result, the gas density is increased, a potential difference is partially generated, and abnormal discharge is easily generated suddenly. When the abnormal discharge occurs, the ion density in the plasma becomes non-uniform, and the etching of the gas blowing plate 83 proceeds locally earlier and reaches the portion of the maximum diameter d1. As a result, the flow rate distribution of the reaction gas becomes non-uniform, the wafer etching rate fluctuates, and the device performance is greatly reduced.

  In order to prevent this, conventionally, when the accumulated time of the RF power discharge reaches a predetermined time, it is determined that the gas blowing plates 81 and 83 are to be replaced, and the gas blowing plates are replaced with new ones. At this time, since the gas blowing plates 81 and 83 were replaced early in consideration of a certain margin as a measure for maintaining the quality, man-hours for replacement and cost of replacement parts were increased. In addition, since the apparatus is stopped for a certain period of time for each replacement work, there is a problem that the apparatus operation rate and productivity are lowered.

  Also in the dry etching apparatus 71 shown in FIG. 5, in order to make the flow rate of the reaction gas supplied into the vacuum chamber 52 uniform, a plurality of gas supply pipes 72a to 72c, supply valves 73a to 73c, and gas flow rate adjustment are performed. The part 74 and a gas sensor (not shown) are required, and there is a problem that the mechanism becomes complicated and the apparatus becomes very expensive.

  The present invention has been conceived to solve the above-described problems, and prevents the reaction product from adhering to the blowout holes, reduces the replacement frequency, and further uniforms the flow rate of the reaction gas supplied to the wafer. An object of the present invention is to provide a dry etching apparatus provided with a gas blowing plate that can be made.

  In order to achieve the above object, a dry etching apparatus according to claim 1 of the present invention includes an upper electrode and a lower electrode which are arranged to face each other at a predetermined interval in a vacuum chamber, and are fixed to the upper electrode. A dry etching apparatus for processing a material to be etched by introducing a reaction gas from a gas blowing plate into a processing chamber and generating plasma between both electrodes, wherein the gas blowing plate is provided with a plurality of blowing holes, and The blowout hole is composed of a large hole portion and a small hole portion having different hole diameters, and the depth of the large hole portion is shallower than the depth of the small hole portion. According to this configuration, since the reaction gas is ejected at a high pressure from the introduction side of the ejection hole provided in the gas ejection plate to the ejection side, it is possible to suppress the plasma in the vacuum chamber from flowing into the ejection hole. Furthermore, even if the gas blowing plate is etched by the reactive gas, the diameter of the blowing hole is kept constant over a long period of time, so that the reactive gas can be stably supplied to the wafer.

  The dry etching apparatus according to claim 2 is the dry etching apparatus according to claim 1, wherein the depth of the large hole portion is not less than 0.5 mm and not more than 1.0 mm. According to this configuration, since the reaction gas is ejected at a high pressure from the introduction side of the ejection hole provided in the gas ejection plate to the ejection side, it is possible to suppress the plasma in the vacuum chamber from flowing into the ejection hole. Furthermore, even if the gas blowing plate is etched by the reactive gas, the diameter of the blowing hole is kept constant for the longest period, so that the reactive gas can be stably supplied to the wafer.

  The dry etching apparatus according to claim 3 is the dry etching apparatus according to claim 1 or 2, wherein the hole diameter of the small hole portion is increased substantially in proportion to the distance from the center of the gas blowing plate. It is characterized by being formed. According to this configuration, since the hole diameter of the small hole portion formed in the gas blowing plate is changed according to the flow rate distribution of the reaction gas supplied from the gas supply pipe, the reaction gas with a uniform flow rate can be stably supplied to the wafer. Can supply.

  The dry etching apparatus according to claim 4 is the dry etching apparatus according to claims 1 to 3, wherein a number of monitor pins for monitoring the etching state of the gas blowing plate are provided between the blowing holes. It is characterized by being. According to this configuration, it is possible to easily and accurately know the replacement timing of the gas blowing plate by examining the relationship between the etching amount of the monitor pin and the integration time of the RF power discharge of the dry etching apparatus.

  A dry etching apparatus according to a fifth aspect is the dry etching apparatus according to the first to fourth aspects, wherein the thickness of the gas blowing plate is 3 mm or more and 20 mm or less. According to this configuration, it is possible to obtain a gas blowing plate that satisfies the mechanical strength, material cost, and workability of the blowing hole.

  The dry etching apparatus according to claim 6 is the dry etching apparatus according to claims 1 to 5, wherein the gas blowing plate is made of one of carbon, silicon, aluminum, and silicon carbide. Features. According to this configuration, even when the gas blowing plate is etched, the generation of particles is small, and a high-quality semiconductor element can be obtained.

  As described above, according to the dry etching apparatus of the present invention, a large number of blowing holes including a large hole portion on the reaction gas introduction side and a small hole portion on the ejection side are provided, and the depth of the large hole portion is reduced to 0. Since the thickness is not less than 0.5 mm and not more than 1.0 mm, the reaction gas does not stay in the large hole portion, and is smoothly ejected from the introduction side to the ejection side at a high pressure, and the wraparound of the plasma to the ejection hole is suppressed. Thereby, it is possible to prevent the reaction product from adhering to the inner wall of the blowout hole and the surface of the gas introduction part, and the number of cleanings can be reduced. In addition, the occurrence of abnormal discharge due to the retention of the reaction gas is suppressed, so that even if the gas blowing plate is etched by the reaction gas, the hole diameter of the small hole portion is kept constant for a long period of time, and the reaction at a stable flow rate on the wafer. Gas can be supplied, and the service life of the gas blowing plate can be extended. Thereby, the replacement frequency of the gas blowing plate can be reduced, and the operating rate and productivity of the apparatus can be improved.

  In addition, since the hole diameter of the small hole portion of the gas blowing plate is increased in proportion to the distance from the center of the gas blowing plate according to the flow rate distribution of the reaction gas coming out of the gas supply pipe, a complicated mechanism can be used. The flow rate of the reaction gas supplied to the wafer can be made uniform without necessity. Thereby, even when the wafer size is large, the etching rate in the wafer surface can be made uniform.

  Moreover, since a number of monitor pins for monitoring the etching state of the gas blowing plate are provided, it is possible to know the replacement timing of the gas blowing plate easily and accurately.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1A to 1C are a cross-sectional view of a dry etching apparatus according to a first embodiment of the present invention, and a cross-sectional view and a plan view of a gas blowing plate used therefor. In a dry etching apparatus 1 shown in FIG. 1A, an upper electrode 3 and a lower electrode 4 are disposed in a vacuum chamber 2 so as to face each other, and a wafer 5 that is an object to be etched is placed on the lower electrode 4. ing. The upper electrode 3 is hollow, and the reaction gas is supplied from the gas supply pipe 6 therein, and is connected to the ground and held at zero potential. A gas supply source 9 is connected to the gas supply pipe 6 via a gas supply valve 7 and a gas flow rate adjusting unit 8. In addition, a high frequency power supply 11 is electrically connected to the lower electrode 4 via a matching unit 10. Furthermore, a vacuum pump 14 such as a turbomolecular pump, a mechanical booster pump, or a rotary pump is connected to the gas exhaust pipe 12 at the lower part of the vacuum chamber 2 through a pressure control valve 13 for exhausting the reaction gas. . Further, a ring-shaped anode cover 15 and a gas blowing plate 21 for supplying a reaction gas into the vacuum chamber 2 are attached to the upper electrode 3.

  As shown in FIGS. 1B and 1C, the gas blowing plate 21 is made of carbon having a thickness t of 3 mm to 20 mm, and a large number of blowing holes 22 are provided on the entire surface. Further, the blowout hole 22 includes a cylindrical large hole portion 23 provided on the reaction gas introduction side and a cylindrical small hole portion 24 provided on the discharge side. The hole diameter d1 of the large hole portion 23 is 0.6 mm to 6.0 mm, the hole diameter d2 of the small hole portion 24 is 0.3 mm to 3.0 mm, and the hole diameter d1 of the large hole portion 23 is the hole diameter d2 of the small hole portion 24. 2 times or more. By setting the hole diameters d1 and d2 of the large hole portion 23 and the small hole portion 24 within this range, it becomes easy to control the flow rate, pressure, and the like of the reaction gas, and a stable flow rate of the reaction gas can be supplied.

  This embodiment is characterized in that the depth t1 of the large hole portion 23 in the gas blowing plate 21 is formed to be shallower than the depth t2 of the small hole portion 24. The gas blowing hole 83 shown in FIG. 6B of Japanese Patent Laid-Open No. 2001-223204 (Patent Document 2) described above is provided with a cylindrical blowing hole 84 having a different diameter. Is deep and substantially the same depth as the portion of the minimum diameter d2, the reaction gas tends to stay in this portion, the gas density increases, and a potential difference is partially generated and suddenly occurs. Abnormal discharge tends to occur. In the gas blowing plate 21 of the present embodiment, the depth t1 of the large hole portion 23 is set to 0.5 mm or more and 1.0 mm or less, and is formed to be shallower than the depth t2 of the small hole portion 24. The retention of the reaction gas can be effectively prevented. When the depth t1 of the large hole portion 23 is smaller than 0.5 mm, the effect of increasing the pressure of the reaction gas is reduced. On the other hand, when it is larger than 1.0 mm, the reactive gas stays and abnormal discharge is likely to occur.

  Further, the hole diameters d1 and d2 of the large hole portion 23 and the small hole portion 24 are formed such that d2 <d1 <L / 2 with respect to the center distance L between the adjacent blowout holes 22. The gas blowing plate 21 is processed using a diamond drill or a laser beam. First, the large hole portion 23 is formed, and then the small hole portion 24 is formed from the same direction. Thereby, the center of the large hole part 23 and the small hole part 24 can be made to correspond.

  Next, the operation of the gas outlet plate 21 of this embodiment will be described. First, when the reaction gas is supplied from the introduction side of the gas blowing plate 21, it flows from the large hole portion 23 toward the small hole portion 24, the pressure of the reaction gas is increased, and the flow velocity is increased. As a result, the reaction gas is ejected at a high pressure from the introduction side of the gas ejection plate 21 to the ejection side, and the plasma 25 in the vacuum chamber 2 is suppressed from entering the ejection hole 22. Adhesion of reaction products can be prevented. Furthermore, since the depth t1 of the large hole portion 23 is designed to be shallow, even if the depth t2 of the small hole portion 24 becomes relatively deep and the gas blowing plate 21 is etched, Since the hole diameter d2 of the small hole portion 24 provided on the ejection side is kept constant, a stable gas flow rate is secured, and the service life of the gas blowing plate 21 can be extended.

  Next, another preferred embodiment will be described with reference to the drawings. FIGS. 2A and 2B are a sectional view and a plan view of a gas outlet plate according to a second embodiment of the present invention. In the gas blowing plate of the present embodiment, the difference from the first embodiment described above is that the diameter of the small hole portion is set to the center of the gas blowing plate in order to stably supply the reaction gas having a uniform flow rate to the wafer. It was increased in proportion to the distance from.

  As shown in FIGS. 2 (a) and 2 (b), the gas blowing plate 31 of this embodiment is provided with a large number of blowing holes 32 on the entire surface. The blowout hole 32 includes a cylindrical large hole portion 33 provided on the reaction gas introduction side and a cylindrical small hole portion 34 provided on the discharge side, and the hole diameter d2 of the small hole portion 34 is the gas blowout plate 31. It is formed so as to increase from the center to the outer periphery. The hole diameter d1 and depth t1 of the large hole portion 33 and the depth t2 of the small hole portion 34 are the same as those in the first embodiment, and d2 <d1 <with respect to the distance L between the centers of the adjacent blowout holes 32. It is formed to be L / 2.

  As shown in the dry etching apparatus 1 in FIG. 1A, the gas supply pipe 6 for supplying the reaction gas is fixed to the central portion of the upper electrode 3, so that the reaction is inevitably performed near the central portion of the upper electrode 3. The gas flow rate becomes the largest and becomes smaller toward the outer periphery. As a result, a difference occurs in the etching rate between the central portion and the outer peripheral portion of the wafer 5. In order to eliminate this difference in etching rate, in the gas blowing plate 31 of the present embodiment, the hole diameter d2 of the small hole portion 34 provided on the ejection side is changed according to the flow rate distribution of the reaction gas exiting from the gas supply pipe 6. ing. For example, the hole diameter d2 of each small hole portion 34 formed at a position where the distance from the center of the gas blowing plate 31 is 10 mm, 20 mm, and 30 mm is set to 0.3 mm, 0.6 mm, and 0.9 mm.

  Thus, by reducing the hole diameter d2 at the central portion where the gas flow rate is large and increasing the hole diameter d2 at the outer peripheral portion where the gas flow rate is small, the flow rate of the reaction gas that has passed through the gas blowing plate 31 is further higher than that in the first embodiment. It becomes uniform and the etching rate in the wafer 5 surface becomes more uniform.

  Next, another preferred embodiment will be described with reference to the drawings. FIGS. 3A and 3B are a sectional view and a plan view of a gas outlet plate according to a third embodiment of the present invention. In the gas blowing plate of the present embodiment, the difference from the second embodiment described above is that a monitor pin for monitoring the etching state of the gas blowing plate is provided in order to easily and accurately grasp the replacement timing of the gas blowing plate. A large number are provided between the blowout holes.

  As shown in FIGS. 3A and 3B, the gas blowing plate 41 of this embodiment is provided with a large number of blowing holes 32 on the entire surface. The blowout hole 32 includes a cylindrical large hole portion 33 provided on the reaction gas introduction side and a cylindrical small hole portion 34 provided on the discharge side, and the hole diameter d2 of the small hole portion 34 is the gas blowout plate 31. It is formed so as to increase from the center to the outer periphery. Further, a large number of monitor pins 42 for monitoring the etching state of the gas blowing plate 41 are provided between the respective blowing holes 32 at a predetermined interval. The monitor pin 42 is made of the same material as the gas blowing plate 41 and carbon. The upper portion 43 has a diameter larger than that of the lower portion 44, and a hole 45 having substantially the same shape provided in advance in the gas blowing plate 41 has a gap from above. It fits and is fixed.

  Next, an etching monitoring method using the monitor pins 42 of the gas blowing plate 41 of this embodiment will be described. In the dry etching apparatus 1 shown in FIG. 1A, after the reaction gas is supplied from the gas supply pipe 6 into the vacuum chamber 2 and exhausted to the vacuum pump 14, the inside of the vacuum chamber 2 reaches a predetermined pressure. By applying a high frequency voltage between the upper electrode 3 and the lower electrode 4, plasma 25 is generated in the upper space of the lower electrode 4, and the wafer 5 on the lower electrode 4 is etched. At the same time, the gas blowing plate 41 shown in FIGS. 3A and 3B is also exposed to the plasma, so that it is etched in the same manner as the wafer 5. After etching a certain number of wafers 5, the monitor pins 42 are removed from the gas blowing plate 41 and the etching amount is measured. Thereafter, the relationship between the etching amount of the gas blowing plate 41 and the integrated time of the RF power discharge of the dry etching apparatus 1 is examined, and the service life of the gas blowing plate 41 is estimated.

  In the gas blowout plate 41 of the present embodiment, a plurality of monitor pins 42 are provided at predetermined intervals between the gas blowout holes 22, and further provided on different circumferences of the gas blowout plate 41. The in-plane distribution can be easily measured.

  In each of the above-described embodiments, carbon is used as the material for the gas blowing plates 21, 31, 41. However, silicon, aluminum, or silicon carbide may be used instead of carbon. These materials generate few particles even when etched, and a high-quality semiconductor element can be obtained.

  By providing a large number of blowing holes consisting of a large hole portion on the reaction gas introduction side and a small hole portion on the ejection side, and by setting the depth of the large hole portion to 0.5 mm or more and 1.0 mm or less, the reaction gas becomes large. There is no stagnation in the hole, and the gas is smoothly ejected from the introduction side to the ejection side at a high pressure, and the wraparound of the plasma to the ejection hole is suppressed. Thereby, it is possible to prevent the reaction product from adhering to the inner wall of the blowout hole and the surface of the gas introduction part, and the number of cleanings can be reduced. In addition, the occurrence of abnormal discharge due to the retention of the reaction gas is suppressed, so that even if the gas blowing plate is etched by the reaction gas, the hole diameter of the small hole portion is kept constant for a long period of time, and the reaction at a stable flow rate on the wafer. Gas can be supplied, and the service life of the gas blowing plate can be extended. Thereby, the replacement frequency of the gas blowing plate can be reduced, and the operating rate and productivity of the apparatus can be improved.

Sectional drawing of the dry etching apparatus of 1st Example of this invention, sectional drawing and top view of a gas blowing plate used for it Sectional drawing and top view of the gas blowing plate of 2nd Example of this invention Sectional drawing and top view of the gas blowing plate of 3rd Example of this invention Sectional view of a conventional dry etching system Sectional view of another conventional dry etching apparatus Sectional view of a conventional gas outlet plate

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dry etching apparatus of 1st Example of this invention 2 Vacuum chamber 3 Upper electrode 4 Lower electrode 5 Wafer 6 Gas supply pipe 7 Gas supply valve 8 Gas flow control part 9 Gas supply source 10 Matching device 11 High frequency power supply 12 Gas exhaust pipe DESCRIPTION OF SYMBOLS 13 Pressure control valve 14 Vacuum pump 15 Anode cover 21 Gas blowing plate of 1st Example of this invention 22 Blowing hole 23 Large hole part 24 Small hole part 25 Plasma 31 Gas blowing plate 32 of 2nd Example of this invention 32 Blowing hole 33 Large hole portion 34 Small hole portion 41 Gas blowout plate according to the third embodiment of the present invention 42 Monitor pin 43 Upper portion 44 Lower portion 45 Hole portion 51 Conventional dry etching apparatus 52 Vacuum chamber 53 Upper electrode 54 Lower electrode 55 Wafer 56 Gas supply pipe 57 Gas supply valve 58 Gas flow control unit 59 Gas supply source 60 Matching device 61 High Frequency power source 62 Gas exhaust pipe 63 Pressure control valve 64 Vacuum pump 65 Gas outlet plate 66 Anode cover 67 Air outlet 68 Plasma 71 Other conventional dry etching apparatuses 72a to 72c Gas supply pipes 73a to 73c Gas supply valve 74 Gas flow rate adjusting unit 75 Gas supply source 76a, 76b Partition 81 Gas outlet plate 82 Tapered outlet 83 Gas outlet 84 Cylindrical outlet

Claims (6)

  An upper electrode and a lower electrode are arranged in a vacuum chamber so as to face each other at a predetermined interval. A reaction gas is introduced into a processing chamber from a gas blowing plate fixed to the upper electrode, and plasma is generated between both electrodes. In the dry etching apparatus for processing the material to be etched, the gas blowing plate is provided with a large number of blowing holes, and the blowing holes are composed of a large hole portion and a small hole portion having different hole diameters, and A dry etching apparatus characterized in that the depth is shallower than the depth of the small hole portion.   2. The dry etching apparatus according to claim 1, wherein a depth of the large hole portion is 0.5 mm or greater and 1.0 mm or less.   3. The dry etching apparatus according to claim 1, wherein a hole diameter of the small hole portion is formed to be substantially proportional to a distance from a center of the gas blowing plate.   4. The dry etching apparatus according to claim 1, wherein a plurality of monitor pins for monitoring the etching state of the gas blowing plate are provided between the respective blowing holes.   The dry etching apparatus according to claim 1, wherein the gas blowing plate has a thickness of 3 mm or more and 20 mm or less.   6. The dry etching apparatus according to claim 1, wherein the gas blowing plate is made of one of carbon, silicon, aluminum, and silicon carbide.

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