Method for manufacturing electrode plate for plasma processing device and electrode plate for plasma processing device

Abstract

A manufacturing method of an electrode plate (11) for a plasma processing apparatus, in which a plurality of gas holes (21) having a straight portion (22) of a length of at least 12 mm are formed in a thickness direction of an electrode plate body (12) in a manner of being parallel to each other and in a through state, the manufacturing method has: a pre-hole forming step of forming a pre-hole (23) from one face of the electrode plate body (12) using a first drill bit (31), the pre-hole (23) having a diameter of 50% or more and 80% or less of a diameter of a hole in which the straight portion (22) is formed; and a straight portion forming step of forming the straight portion (22) in a manner of overlapping the pre-hole (23) using a second drill bit (32).

Description

Technical Field

[0001] This invention relates to a method for manufacturing an electrode plate for a plasma processing device and the electrode plate for the plasma processing device.

[0002] This application claims priority based on Japanese Patent Application No. 2020-053222, filed on March 24, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] In plasma processing apparatuses used in semiconductor device manufacturing processes, such as plasma etching apparatuses or plasma CVD apparatuses, upper and lower electrodes connected to a high-frequency power supply are arranged, for example, facing each other vertically within a chamber. The lower electrode is configured to have a substrate to be processed mounted on it, and the upper electrode has a vent hole through which etching gas flows to the substrate while a high-frequency voltage is applied. Thus, the plasma processing apparatus generates plasma and performs etching or other processing on the substrate.

[0004] Patent Document 1 discloses an electrode plate for plasma etching that suppresses particle generation. This electrode plate has through-holes (pores) arranged parallel to the thickness direction of the electrode plate formed from single-crystal silicon. The through-holes consist of large-diameter straight hole portions and small-diameter straight hole portions. According to this electrode plate, large particles are not generated, reducing the number of cleaning cycles and enabling more efficient plasma etching of silicon wafers than before.

[0005] Thicker electrode plates generally have longer lifespans. Recently, there have been cases where deep etching is necessary, such as with complex multilayer three-dimensional structures of the substrate being processed (e.g., 3D NAND), necessitating increased etching gas pressure. This accelerates the depletion of pores, leading to shorter lifespans for previously thicker electrode plates. Therefore, thicker electrode plates are needed to further extend their lifespan.

[0006] On the other hand, there are methods for machining pores in electrode plates, including drilling, laser machining, water jet machining, and electrical discharge machining. Laser machining can only drill holes a few millimeters deep (approximately 5mm). Water jet machining cannot effectively shape the opening of the pores. Electrical discharge machining requires materials that are electrically charged. In comparison, drilling has advantages in terms of machinability, versatility, and quality.

[0007] Patent Document 1: Japanese Patent Application Publication No. 2001-102357

[0008] However, even in this drilling process, for example, when the diameter of the pore is 0.5mm to 1.0mm and the depth increases, due to the processing load, there may be problems such as drill bit shaking and the roundness of the pore becoming larger (worse), which may reduce the quality of plasma treatment. Summary of the Invention

[0009] The present invention was made in view of the above circumstances, and its object is to provide a method for manufacturing an electrode plate for a plasma processing device that can form pores with small roundness even when processing pores with a depth of more than 12 mm, and an electrode plate for a plasma processing device having pores with small roundness.

[0010] According to one aspect of the present invention, a method for manufacturing an electrode plate for a plasma processing apparatus forms a plurality of pores in a parallel and penetrating manner along the thickness direction of the electrode plate body. The plurality of pores have straight portions with a length exceeding 12 mm. The method for manufacturing the electrode plate for the plasma processing apparatus includes: a pre-hole forming step in which a pre-hole is formed from one side of the electrode plate body using a first drill bit, the diameter of the pre-hole being 50% or more and 80% or less of the diameter of the straight portion; and a straight portion forming step in which the straight portion is formed using a second drill bit in a manner overlapping the pre-hole.

[0011] According to the manufacturing method of the electrode plate for the plasma processing device, after forming a pre-hole with a diameter of 50% to 80% of the diameter of the straight section using a first drill bit, the straight section is formed using a second drill bit. Therefore, the second drill bit performs hole machining with a lower machining load, reducing the cutting area of ​​the pre-hole area compared to the overall cutting area of ​​the original straight section. Because the machining load of the second drill bit is reduced, its machining accuracy can be improved, and a straight section with less roundness can be formed. In this case, if the diameter of the pre-hole is less than 50% of the diameter of the straight section, the effect of reducing the machining load of the second drill bit is less significant; if it exceeds 80%, the machining load of the smaller-diameter first drill bit becomes larger, and the first drill bit may break.

[0012] As the machining depth increases (the electrode plate becomes thicker), the machining load on the drill bit also increases, making it prone to buckling. Therefore, single-crystal diamond drill bits, polycrystalline diamond drill bits, sintered drill bits, and drill bits with oil filler ports, which are highly resistant to buckling strength and machining load, can be used. The following manufacturing methods can avoid the risk of drill bit breakage caused by machining load.

[0013] In one aspect of the manufacturing method of the present invention, it is preferable that, in the pre-hole forming step, a pre-hole is formed using the first drill bit, and the pre-hole is formed up to the midpoint of the thickness of the electrode plate body. In this case, it is preferable that the machining depth of the pre-hole exceeds 5 mm.

[0014] According to the manufacturing method of the electrode plate for the plasma processing device, before forming pores on the electrode plate body, a pre-hole is drilled to the midpoint in the thickness direction. The inner diameter of the pre-hole is 50% to 80% of the inner diameter of the straight portion of the pore. Since the pre-hole only needs to be formed to the midpoint in the thickness direction of the electrode plate body, the cutting length of the first drill bit can be shorter than the thickness of the electrode plate body. That is, even if the diameter of the first drill bit used for pre-holeing is small, its short length makes it less prone to breakage.

[0015] In this case, when the length of the pre-hole is less than 5 mm relative to the straight section with a length exceeding 12 mm, the effect of reducing the machining load of the second drill bit is less, so it is best to form the pre-hole with a length exceeding 5 mm.

[0016] On the other hand, the second drill bit is a drill bit with a diameter larger than that of the first drill bit, and it performs hole machining on the pre-drilled hole drilled by the first drill bit, for example, in a coaxial manner from the same direction as the pre-drilled hole. Here, since the second drill bit performs hole machining in a coaxial manner with the pre-drilled hole, the machining load can be reduced by an amount equivalent to the amount of pre-drilled hole cutting area that has been removed. Therefore, the second drill bit can perform hole machining with a smaller machining load than the pre-drilled hole cutting area, which is reduced from the original straight section as a whole. Therefore, the second drill bit is less prone to buckling caused by the cumulative increase in machining load. As a result, even if the cutting length of the second drill bit is longer than that of the first drill bit, the risk of breakage is correspondingly reduced due to the reduced machining load.

[0017] Preferably, the second drill bit is used to machine the hole in a manner coaxial with the pre-hole formed by the first drill bit, but slight deviations within the diameter difference between the two drill bits are permissible.

[0018] In one aspect of the manufacturing method of the present invention, the second drill bit can perform hole machining from one side of the electrode plate body or from the other side of the electrode plate body.

[0019] In the manufacturing method of the electrode plate for this plasma processing device, when the second drill bit performs hole machining from the other side of the electrode plate body, the hole machining is performed from the opposite direction to when the first drill bit forms the pre-hole. Even in this case, the second drill bit performs hole machining in a manner approximately coaxial with the pre-hole, thereby reducing the machining load after reaching the pre-hole cutting area that has been removed from one side by an amount equivalent to the pre-hole cutting area. Therefore, compared to machining the entire original pore, the overall machining load is also reduced. When the second drill bit reaches a predetermined depth from the other side, it connects with the pre-hole formed from one side. After this, the machining load for the second drill bit can be reduced by an amount equivalent to the pre-hole cutting area.

[0020] Therefore, the second drill bit can perform hole machining from the middle of the thickness direction (after reaching the pre-hole cutting area) with a lower machining load than the original straight section's overall cutting area, which is reduced by the pre-hole cutting area. Thus, in the second drill bit, the reduced machining load starting from the middle of the thickness direction makes buckling less likely to occur due to the cumulative increase in machining load. That is, even if the cutting length of the second drill bit is longer than that of the first drill bit, the risk of breakage is correspondingly reduced due to the reduced machining load.

[0021] As a method to make the machining of the first drill bit and the machining of the second drill bit coaxial, a hole other than a vent hole can be used as a reference hole, and its position information can be set in the machining center (machine tool). By setting the machining positions of the first drill bit and the second drill bit to the same coordinates, coaxial machining can be performed. The same applies when the second drill bit is machining a hole from the other side of the electrode plate body. Furthermore, regarding the change from the first drill bit to the second drill bit, coaxial replacement is usually performed automatically from the drill bit changer (drill bit, tool storage) in the machining center via an automatic change function.

[0022] In one aspect of the manufacturing method of the present invention, when the second drill bit performs hole machining from the other side of the electrode plate body, the straight section can be formed, which reaches the pre-hole and is formed up to the middle of the thickness of the electrode plate body.

[0023] The pores formed by this manufacturing method are stepped holes with small-diameter pre-drilled holes on one side of the electrode plate body and large-diameter holes forming straight sections on the other side. In this case, the machining load of each drill bit can also be reduced, making it suitable for thick electrode plates.

[0024] According to one aspect of the present invention, the electrode plate for a plasma processing apparatus is an electrode plate for a plasma processing apparatus having a plurality of air holes arranged in parallel and through each other in the thickness direction of the electrode plate body. The air holes have a straight portion with a length of more than 12 mm, the diameter of the straight portion is more than 0.5 mm and less than 1.0 mm, and the roundness is less than 0.01 mm.

[0025] According to the electrode plate used in this plasma processing device, the length of the straight section is at least 12 mm, so the electrode plate body is formed with a thickness of more than 12 mm, which can extend its service life. In addition, since the roundness of the straight section is less than 0.01 mm, it is less likely to cause non-uniformity in gas flow.

[0026] In the electrode plate of this plasma processing device, a small-diameter portion opening on one side of the electrode plate body and a large-diameter portion opening on the other side of the electrode plate body can be connected in the thickness direction through the pores, wherein the large-diameter portion is the straight portion.

[0027] According to the method for manufacturing an electrode plate for a plasma processing apparatus according to the above-described manner of the present invention, even when machining pores in an electrode plate for a plasma processing apparatus with a thickness exceeding 12 mm, the risk of drill bit breakage can be reduced, thereby enabling the formation of high-precision pores. Based on this electrode plate for a plasma processing apparatus, its service life can be extended due to the thickness of the electrode plate. Furthermore, since the roundness of the straight portion is less than 0.01 mm, gas flow non-uniformity is less likely to occur. Attached Figure Description

[0028] Figure 1 This is a plan view of the electrode plate for the plasma processing apparatus according to an embodiment of the present invention.

[0029] Figure 2 yes Figure 1 Longitudinal cross-section of the main part.

[0030] Figure 3 This is a cross-sectional view showing the state of pre-holes formed in the pre-hole forming process in the manufacturing method of the embodiment.

[0031] Figure 4 This is a cross-sectional view showing the state in which a straight section is formed in the same direction as the pre-hole in the straight section forming process after the pre-hole forming process.

[0032] Figure 5 This is a cross-sectional view showing the state of forming a straight section from the opposite direction to the pre-hole in the straight section forming process after the pre-hole forming process.

[0033] Figure 6 This is a cross-sectional view showing an example of a pore with a stepped shape formed by a pre-hole and a straight section.

[0034] Figure 7 This is a cross-sectional view showing the state after the pre-hole forming process, in order to form a straight section extending to the midpoint of the thickness direction of the electrode plate body, with a second drill bit in place.

[0035] Figure 8 This is a cross-sectional view showing a hole with a diameter smaller than that of a straight section formed by a third drill bit along the thickness direction of the electrode plate body.

[0036] Figure 9 It means through Figure 8 A cross-sectional view of the pores with a stepped shape formed by the method shown. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0038] Figure 1This is a plan view of the electrode plate for the plasma processing apparatus according to an embodiment of the present invention.

[0039] Regarding the electrode plate (hereinafter also simply referred to as "electrode plate") 11 for the plasma processing apparatus, a plurality of pores 21 are formed on the electrode plate body 12, which is formed from monocrystalline silicon, columnar silicon, or polycrystalline silicon into a circular plate with a thickness t exceeding 12 mm and less than 30 mm and a diameter of 200 mm and less than 550 mm. These pores are spaced a few millimeters to 10 mm apart, for example, in a longitudinal and transverse arrangement, penetrating parallel to each other along the thickness direction. In this case, there are several hundred to 1000, at least 100, or at least 500 pores. Each pore 21 has a straight portion 22 with a length of at least 12 mm in the thickness direction of the electrode plate body 12. Figure 2 In the example shown, the pore 21 is formed in a straight shape along the entire thickness of the electrode plate body 12. Therefore, the straight portion 22 of this embodiment constitutes the entire length of the pore 21, which is more than 12 mm. The diameter d of the straight portion 22 is more than 0.5 mm and less than 1.0 mm, and the roundness is less than 0.01 mm.

[0040] The electrode plate 11 for the plasma processing device is manufactured by etching, polishing, and other processes after forming pores on the disc-shaped electrode plate body 12 obtained by slicing silicon ingots such as single-crystal silicon.

[0041] The formation of pores includes: a pre-hole forming step, in which a pre-hole 23 is formed from one side of the electrode plate body 12 to the middle of the thickness of the electrode plate body 12 using a first drill bit 31, wherein the diameter of the pre-hole 23 is more than 50% and less than 80% of the diameter of the hole forming the straight section 22; and a straight section forming step, in which a straight section 22 is formed by using a second drill bit 32 to overlap with the pre-hole 23, thereby forming pores 21.

[0042] Drill bits 31 and 32 can be made of sintered tungsten (W) material, electroplated with diamond particles, polycrystalline diamond, or monocrystalline diamond. The selection of these drill bits revealed that, particularly in the case of monocrystalline diamond, they are preferred due to the minimal number of broken pieces.

[0043] To explain the pore formation process in more detail, firstly, in the pre-hole formation process, a pre-hole 23 is machined up to the midpoint of the thickness of the electrode plate body 12. The inner diameter of the pre-hole 23 is 50% to 80% of the inner diameter of the straight portion 22 of the pore 21. If the diameter of the straight portion 22 is 0.5 mm to 1.0 mm, for example, the diameter of the pre-hole 23 is 0.3 mm to 0.8 mm. The pre-hole 23 is machined using a first drill bit 31 up to the midpoint of the thickness of the electrode plate body 12, for example, to a depth L1 of approximately 8 mm. Therefore, the diameter d1 of the first drill bit 31 is smaller than the diameter of the straight portion 22. Figure 3 This indicates that the pre-hole 23 is processed by the first drill bit 31. After processing to a depth of about L1 = 8mm, the first drill bit 31 is pulled out from the pre-hole 23.

[0044] Next, in the process of forming the straight section, a straight section 22 with a diameter greater than that of the pre-hole 23 and ranging from 0.5 mm to 1.0 mm is machined using the second drill bit 32 and penetrates the electrode plate body 12. For example, the straight section 22 is formed with a diameter approximately 0.2 mm larger than that of the pre-hole 23 (0.1 mm larger on each side). Therefore, the diameter d2 of the second drill bit 32 is greater than the diameter d1 of the first drill bit 31.

[0045] exist Figure 3 and Figure 4 In the diagram, the pre-hole cutting area 41 formed in the pre-hole forming process is represented by a solid line, while the straight section cutting area 42, which should be formed in the straight section forming process, is represented by a dashed line. Figure 3 and Figure 4 In the example shown, the second drill bit 32 performs hole machining from the same direction as the first drill bit 31 when machining the pre-hole 23, and in a manner coaxial with the pre-hole 23. In the straight section forming process, the second drill bit 32 performs hole machining until it penetrates the electrode plate body 12. Therefore, the straight section 22 is formed over the entire thickness of the electrode plate body 12.

[0046] In the above manufacturing method, before the pore 21 is formed on the electrode plate body 12, the pre-hole 23 is formed up to the midpoint in the thickness direction. The inner diameter of the pre-hole 23 is 50% to 80% of the inner diameter of the straight portion 22 of the pore 21. Since the pre-hole 23 only needs to be formed up to the midpoint in the thickness direction of the electrode plate body 12, the cutting length of the first drill bit 31 can be shorter than the thickness of the electrode plate body 12. That is, although the diameter of the first drill bit 31 used to form the pre-hole is small, its short length makes it less prone to breakage.

[0047] Although the diameter of the second drill bit 32 is larger than that of the first drill bit 31 and its length is longer, with a straight length exceeding 12 mm, the second drill bit 32 can perform hole machining from above the pre-hole 23 already drilled by the first drill bit 31, coaxially with the pre-hole 23, until it penetrates the electrode plate body 12. That is, by machining the hole coaxially with the pre-hole 23, the machining load is reduced by an amount equivalent to the amount of pre-hole cutting area 41 that has been removed. Therefore, the second drill bit 32 can perform hole machining with less machining load, reducing the pre-hole cutting area 41 from the overall cutting area of ​​the original air hole 21 (straight section 22). Therefore, the second drill bit 32 is less prone to buckling due to the cumulative increase in machining load. As a result, even if the cutting length of the second drill bit 32 is longer than that of the first drill bit 31, the risk of breakage is correspondingly reduced due to the reduced machining load. As described above, the diameters of the first drill bit 31 and the second drill bit 32 are different. Therefore, the pores 21 of the electrode plate body 12 are formed by at least two drill bits (e.g., the first drill bit 31 and the second drill bit 32) with different diameters.

[0048] Although the second drill bit 32 is preferably used to machine the pre-hole 23 formed by the first drill bit 31 on the coaxial axis, slight deviations within the diameter difference of the two drill bits 31 and 32 are permissible.

[0049] The length of the straight portion 22 is more than 12 mm and less than 30 mm. Correspondingly, the machining depth of the pre-hole 23 drilled by the first drill bit 31 is preferably more than 5 mm and less than 15 mm. If the machining depth of the pre-hole 23 is shallow (less than 5 mm), the machining load on the second drill bit 32 cannot be reduced, potentially leading to breakage or reduced roundness of the second drill bit 32. If the machining depth of the pre-hole 23 is deep, the machining load on the first drill bit 31 increases, potentially leading to breakage of the first drill bit 31. The machining depth of the pre-hole 23 is more preferably 7 mm or more and 13 mm or less. Therefore, if the thickness of the electrode plate body 12 is less than 15 mm, preferably less than 13 mm, the pre-hole 23 drilled by the first drill bit 31 can be formed by penetrating the electrode plate body 12.

[0050] In the electrode plate 11 obtained by this manufacturing method, the pores 21 have straight portions 22 with a length of at least 12 mm. Figure 2 In the example shown, the entire length of the vent 21 is a straight section 22. The diameter of the straight section 22 is 0.5 mm or more and 1.0 mm or less, and the roundness is 0.01 mm or less.

[0051] According to the electrode plate 11, the length of the straight portion 22 is at least 12 mm, so the electrode plate body 12 is formed with a thickness of more than 12 mm, which can extend the service life. In addition, since the roundness of the straight portion 22 is less than 0.01 mm, it is not easy to generate uneven gas flow.

[0052] When using two drill bits for hole machining, the following method can also be considered.

[0053] (1) The outer diameters of the two drill bits are set to be the same as the outer diameters that can form the final air holes. The first drill bit is used to drill the hole up to the middle of the thickness of the electrode plate body, and the second drill bit is used to drill the hole a second time from above the hole to penetrate the electrode plate body.

[0054] (2) Setting the outer diameter of the two drill bits to be the same as the outer diameter that can form the final air hole, performing the first hole machining using the first drill bit up to the middle of the thickness of the electrode plate body, and inserting the front end of the second drill bit into the hole, performing the second hole machining from the end of the hole that has already undergone the first hole machining to penetrate the electrode plate body.

[0055] In these methods (1) and (2), a short-cutting-length drill bit can be used during the first hole machining, thus reducing the risk of drill bit breakage. However, a positional shift occurs between the first and second machined holes, causing deformation at the hole's opening end and potentially reducing the hole's roundness. During the second hole machining, the drill bit may wobble, further increasing the risk of breakage.

[0056] In this invention, as described above, the second drill bit 32 can perform hole machining from the same direction as the first drill bit 31 that forms the pre-hole 23, or it can perform hole machining from the opposite side of the electrode plate body 12, unlike the first drill bit 31.

[0057] Figure 5 The diagram shows an example where a second drill bit 32, used for machining the straight section 22, forms the straight section in a direction opposite to the forming direction of the pre-hole 23. Figure 3 Similarly, the first drill bit 31 forms a pre-hole 23 by drilling from one side of the electrode plate body 12 to the midpoint of its thickness. Conversely, the second drill bit 32 drills a hole from the other side of the electrode plate body 12 (the side opposite to the first side, or the side opposite to the first side) coaxial with the pre-hole 23 until it penetrates the electrode plate body 12. Thus, a straight portion 22 penetrating the entire thickness of the electrode plate body 12 can be formed. Therefore, the shape of the formed pore 21 is similar to... Figure 3 and Figure 4 The processing conditions shown are the same, becoming as follows: Figure 2 The straight shape shown.

[0058] In this invention, the straight portion 22 does not necessarily have to be formed to extend through the electrode plate body 12.

[0059] Figure 6 Is and Figure 5 Similarly, a straight section 22 is formed from the side opposite to the pre-hole 23 in the electrode plate body 12. However, the straight section 22 only has a depth L2 that reaches the front end of the pre-hole 23, that is, only reaches the middle of the thickness of the electrode plate body 12, thereby forming a stepped vent 211 that connects the pre-hole 23 and the straight section 22.

[0060] In this case, the pre-hole 23 becomes a small-diameter portion 24 formed from one side of the electrode plate body 12 to the midpoint in the thickness direction. The straight portion 22 becomes a large-diameter portion 25 formed from the other side of the electrode plate body 12, coaxial with the small-diameter portion 24, and extending to the midpoint in the thickness direction of the electrode plate body 12. Thus, a stepped-shaped vent 211 is formed in the electrode plate body 12 by connecting the small-diameter portion 24 and the large-diameter portion 25.

[0061] pass Figures 3 to 6 The pores 21 and 211 formed by the above method shown have a straight portion 22 with a length of at least 12 mm, the diameter of the straight portion 22 being 0.5 mm or more and 1.0 mm or less, and the roundness being 0.01 mm or less.

[0062] When pores with a stepped shape are formed, it is also possible to... Figures 7 to 9 The method shown is used to form it.

[0063] In this example, the method first involves the first drill bit 31 ( Figures 7 to 8 Illustrations omitted; please refer to the original text. Figure 3 The pre-hole cutting area 41 formed from one side of the electrode plate body 12 to the midpoint of the thickness direction, such as... Figure 7 As shown, a straight section 22 is formed coaxially from the same direction using a second drill bit 32 within a length L2, the straight section 22 extending to the midpoint of the thickness of the electrode plate body 12 (see reference). Figure 8 The third drill bit 33 is used to drill from the other side of the electrode plate body 12 to the depth of the straight section cutting area 42 and to perform hole machining in a coaxial manner. Figure 9 The state shown. In Figures 7 to 9 In the example shown, the diameter of the third drill bit 33 is smaller than that of the second drill bit 32, the straight section 22 is a large-diameter section 25, and the hole formed by the third drill bit 33 is a small-diameter section 24, forming a stepped vent 212 that connects them at the midpoint of the thickness of the electrode plate body 12. In this case, the straight section 22 is also formed to have a length L2 exceeding 12 mm.

[0064] Although the diagram is omitted, the diameter of the third drill bit 33 is set to be smaller than that of the second drill bit 32. However, a third drill bit with a larger diameter than the second drill bit 32 can also be used to process the hole connected to the straight section 22. Thus, the straight section 22 can be set as a small diameter section, and the hole formed by the third drill bit 33 can be set as a large diameter section.

[0065] Example

[0066] Samples were prepared using various hole-machining methods. After hole machining, the diameter and roundness of the opening on the inlet side of the second drill bit were measured using a 3D image measuring machine (QuickVision QVX606-PRO manufactured by Mitutoyo Co., Ltd.) through image processing. The presence or absence of drill bit breakage during machining was also confirmed. Five tests (five hole machining operations) were conducted, and the average values ​​of the hole diameter and roundness were calculated. The number of drill bits that broke in each of the five tests was investigated. Bits with breakage were excluded from the test samples.

[0067] [Example 1]

[0068] A straight hole with a target diameter of 0.8 mm is formed through the electrode plate body with a thickness of 20 mm.

[0069] (1) Processing method A in the past

[0070] A hole was machined from one side of the electrode plate body in one pass using a drill bit with a diameter of 0.8 mm and a cutting length of 20 mm.

[0071] (2) Processing method A of the comparative example

[0072] After machining a 10mm deep pre-hole from one side of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (first drill bit: in the comparative example, the initial drill bit is also referred to as the first drill bit, and the second drill bit is referred to as the second drill bit. The same applies below), a 20mm deep hole was machined from one side of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 20mm (second drill bit) to penetrate the electrode plate body by machining a hole 20mm deep, including the pre-hole.

[0073] (3) Processing method B of the comparative example

[0074] After a 10mm deep pre-hole was machined from one side of the electrode body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (first drill bit), the front end of a drill bit with a diameter of 0.8mm and a cutting length of 20mm (second drill bit) was inserted into the pre-hole, and a hole was machined to a depth of 10mm from the position of the 10mm depth, thus penetrating the electrode plate body.

[0075] (4) Processing method A of the embodiment

[0076] After drilling a 10mm deep pre-hole from one side of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 10mm, a 20mm deep hole was drilled from one side of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 20mm, penetrating the electrode plate body by including the pre-hole.

[0077] These results are shown in Table 1. The evaluation of drill bit breakage in previous cases is recorded in the column for the first drill bit (the same applies to Tables 2 and 3).

[0078] [Table 1]

[0079] Aperture (mm) Roundness (mm) First drill bit damaged Second drill bit damaged Previous example A - - 5 / 5 - Comparative Example A 0.818 0.073 0 / 5 3 / 5 Comparative Example B 0.814 0.065 0 / 5 3 / 5 Example A 0.802 0.005 0 / 5 0 / 5

[0080] In the previous example A, all five tests resulted in drill bit breakage, so the hole diameter and roundness were not measured.

[0081] Comparative examples A and B both resulted in drill bit (second drill bit) breakage in three out of five tests, and the hole diameter had a large error relative to the target hole diameter, and the roundness was also poor.

[0082] In contrast, in the processing method of Example A, it was confirmed that no drill bit was damaged, the error in the diameter of the processed hole was small, and it was possible to process holes with small roundness.

[0083] [Example 2]

[0084] A straight hole with a target diameter of 0.8 mm is formed through the electrode plate body with a thickness of 30 mm.

[0085] (1) Processing method B in the past

[0086] A hole was machined from one side of the electrode plate body in one pass using a drill bit with a diameter of 0.8 mm and a cutting length of 30 mm.

[0087] (2) Processing method C of the comparative example

[0088] After a 10mm deep pre-hole was machined from one side of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (first drill bit), a 30mm deep hole was machined from one side of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 30mm (second drill bit) to penetrate the electrode plate body by including the pre-hole.

[0089] (3) Processing method D of the comparative example

[0090] After a 10mm deep pre-hole was machined from one side of the electrode body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (first drill bit), the front end of a drill bit with a diameter of 0.8mm and a cutting length of 30mm (second drill bit) was inserted into the pre-hole, and a hole was machined to a depth of 20mm from the 10mm position, thus penetrating the electrode plate body.

[0091] (4) Processing method B of the embodiment

[0092] After a 10mm deep pre-hole was machined from one side of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 10mm, a 30mm deep hole was machined from one side of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 30mm, penetrating the electrode plate body by including the pre-hole.

[0093] These results are shown in Table 2.

[0094] [Table 2]

[0095] Aperture (mm) Roundness (mm) First drill bit damaged Second drill bit damaged Previous example B - - 5 / 5 - Comparative Example C - - 0 / 5 5 / 5 Comparative Example D - - 0 / 5 5 / 5 Example B 0.801 0.009 0 / 5 0 / 5

[0096] In previous example B, all five tests resulted in drill bit breakage. In comparative examples C and D, the second drill bit broke in all five tests, so the hole diameter and roundness were not measured.

[0097] In the processing method of Example B, it was confirmed that no drill bit broke, the error in the diameter of the processed hole was small, and holes with small roundness could be processed. As described above, the method of the present invention is also effective when processing air holes with a straight section of 30 mm in length.

[0098] [Example 3]

[0099] A straight hole with a target diameter of 0.8 mm is formed through the electrode plate body with a thickness of 13 mm.

[0100] (1) Processing method C in the past

[0101] A hole was machined from one side of the electrode plate body in one pass using a drill bit with a diameter of 0.8 mm and a cutting length of 13 mm.

[0102] (2) Processing method E of the comparative example

[0103] After a 10mm deep pre-hole was machined from one side of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 10mm (first drill bit), a 13mm deep hole was machined from one side of the electrode plate body using a drill bit with a diameter of 0.8mm and a cutting length of 13mm (second drill bit) to penetrate the electrode plate body by including the pre-hole.

[0104] (3) Processing method F of the comparative example

[0105] After using a drill bit with a diameter of 0.8 mm and a cutting length of 10 mm (first drill bit) to machine a pre-hole with a depth of 10 mm from one side of the electrode body, the front end of a drill bit with a diameter of 0.8 mm and a cutting length of 13 mm (second drill bit) is inserted into the pre-hole, and a hole with a depth of 3 mm is machined from the position with a depth of 10 mm to penetrate the electrode plate body.

[0106] (4) Processing method C of the embodiment

[0107] After a 10mm deep pre-hole was machined from one side of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 10mm, a 13mm deep hole was machined from one side of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 13mm, penetrating the electrode plate body by including the pre-hole.

[0108] (5) Processing method D of the embodiment

[0109] After drilling a 13mm deep pre-hole (through hole) from one side of the electrode plate body using a first drill bit with a diameter of 0.6mm and a cutting length of 13mm, the electrode plate body was fabricated by drilling a 13mm deep hole from one side of the electrode plate body using a second drill bit with a diameter of 0.8mm and a cutting length of 13mm, in a manner including the pre-hole.

[0110] These results are shown in Table 3.

[0111] [Table 3]

[0112] Aperture (mm) Roundness (mm) First drill bit damaged Second drill bit damaged Previous example C 0.805 0.015 3 / 5 - Comparative Example E 0.808 0.035 0 / 5 1 / 5 Comparative Example F 0.807 0.040 0 / 5 1 / 5 Example C 0.802 0.003 0 / 5 0 / 5 Example D 0.803 0.003 1 / 5 0 / 4

[0113] In the previous example C, drill bit breakage occurred in three out of five tests. In comparative examples E and F, second drill bit breakage occurred in one out of five tests. However, because the hole machining depth was less than that of the holes in Examples 1 and 2, drill bit breakage was less frequent. Although the hole machining could be completed, the diameter error of the resulting hole was large, and the roundness did not meet the requirements. It is believed that because the second drill bit in Comparative Example F was machining to a depth of 3mm, the load was relatively small. However, the second drill bit was prone to wobbling in the first hole drilled, resulting in breakage in one out of five tests.

[0114] In Example C, no drill bit broke, the hole diameter error was small, and the roundness was also small.

[0115] In Example D, although it was confirmed that the first drill bit broke in one of the five tests, the error in the borehole diameter was small, and the roundness was also small.

[0116] As can be seen from the above embodiments, according to the manufacturing method of the present invention, even if the electrode plate body is relatively thick, it is possible to form a hole with a straight section length exceeding 12 mm with high precision (small roundness).

[0117] Industrial availability

[0118] According to the manufacturing method of the electrode plate for plasma processing apparatus of the present invention, even when performing pore processing on an electrode plate for plasma processing apparatus with a thickness exceeding 12 mm, the risk of drill bit breakage can be reduced, thereby enabling the formation of high-precision pores. Based on this electrode plate for plasma processing apparatus, the service life can be extended due to the thickness of the electrode plate. Furthermore, since the roundness of the straight portion is less than 0.01 mm, gas flow non-uniformity is less likely to occur.

[0119] Symbol Explanation

[0120] 11. Electrode plate (electrode plate for plasma processing device)

[0121] 12 Electrode Plate Main Body

[0122] 21, 211, 212 stomata

[0123] 22. Straight Section

[0124] 23 Pre-hole

[0125] 24 Small diameter part

[0126] 25 Large diameter section

[0127] 31 First Drill Bit

[0128] 32 Second Drill Bit

[0129] 41 Pre-hole cutting area

[0130] 42. Cutting area of ​​straight section

Claims

1. A method for manufacturing an electrode plate for a plasma processing device, comprising forming a plurality of pores in a parallel and penetrating manner along the thickness direction of the electrode plate body, wherein the plurality of pores have straight portions with a length exceeding 12 mm, the method for manufacturing the electrode plate for the plasma processing device being characterized by having: In the pre-hole forming process, a pre-hole is formed from one side of the electrode plate body using a first drill bit. The diameter of the pre-hole is 50% to 80% of the diameter of the hole forming the straight section. In the straight section forming process, a second drill bit is used to form the straight section in a manner that is coaxial with and overlaps with the pre-hole. In the pre-hole forming process, the processing depth of the pre-hole exceeds 5 mm. In the process of forming the straight section, the straight section is formed from the other side of the electrode plate body using the second drill bit, and the straight section reaches the pre-hole and is formed up to the middle of the thickness of the electrode plate body. The electrode plate body is composed only of monocrystalline silicon, columnar silicon, or polycrystalline silicon. The diameter of the second drill bit is larger than the diameter of the first drill bit. The straight section forming process is performed after the pre-hole forming process.

2. A method for manufacturing an electrode plate for a plasma processing device, wherein a plurality of pores are formed in a parallel and penetrating manner along the thickness direction of the electrode plate body, the plurality of pores having a straight portion with a length exceeding 12 mm, the method for manufacturing the electrode plate for the plasma processing device being characterized by having: In the pre-hole forming process, a pre-hole is formed from one side of the electrode plate body using a first drill bit. The diameter of the pre-hole is more than 50% and less than 80% of the diameter of the hole forming the straight section. In the straight section forming process, the straight section is formed using a second drill bit in a manner that is coaxial with and overlaps with the pre-hole; and The process of forming a hole reaching the straight section from the other side of the electrode plate body using a third drill bit, coaxial with the pre-hole. In the pre-hole forming process, the processing depth of the pre-hole exceeds 5 mm. In the process of forming the straight section, the straight section is formed using the second drill bit from one side of the electrode plate body to the midpoint of the thickness of the electrode plate body. The electrode plate body is composed only of monocrystalline silicon, columnar silicon, or polycrystalline silicon. The diameter of the second drill bit is larger than the diameter of the first drill bit. The diameter of the third drill bit is smaller than the diameter of the second drill bit. The straight section forming process is performed after the pre-hole forming process.

3. The method for manufacturing an electrode plate for a plasma processing apparatus according to claim 1 or 2, characterized in that, The pre-holes are formed up to the midpoint of the thickness of the electrode plate body.

4. An electrode plate for a plasma processing device, characterized in that a plurality of air holes are arranged parallel to each other and in a through-type manner along the thickness direction of the electrode plate body, wherein... The electrode plate body is composed only of monocrystalline silicon, columnar silicon, or polycrystalline silicon. The vent has a straight portion with a length exceeding 12 mm and opening on one side of the electrode plate body, which serves as the gas outlet surface. The diameter of this straight portion is 0.5 mm or more and 1.0 mm or less, and the roundness is 0.01 mm or less. In the pore, a small-diameter portion opening on the other side of the electrode plate body and a large-diameter portion opening on one side of the electrode plate body are connected at midway in the thickness direction, and the large-diameter portion is the straight portion.

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