Method for regenerating film-forming structure and regenerated film-forming structure

Abstract

Provided are a method for regenerating a film-forming structure in a simple and low-cost manner and a regenerated film-forming structure manufactured by the method. The method for regenerating a film-forming structure is characterized by comprising: a new film-forming layer stacking step of stacking a new SiC layer 16 on an inactive surface 10b located on the opposite side of a damaged active surface 10a; and a processing step of processing the active surface 10a to obtain an active surface of a focus ring 10.

Description

Technical Field

[0001] The present invention relates to the regeneration of a structure composed of a film containing SiC, a regeneration method suitable for reducing the regeneration cost of the film-formed structure, and a regenerated structure. Background Art

[0002] When semiconductor manufacturing is performed by plasma etching or the like, SiC components (jigs, etc.) provided in the manufacturing chamber are affected by the plasma etching and part of their surface is corroded (damaged). Compared with cheap Si components, SiC components are less likely to pulverize and have high durability but are expensive. Therefore, research has been conducted on reducing the operating cost when using SiC components by regenerating damaged SiC components, and the technologies disclosed in Patent Documents 1 and 2 have been proposed.

[0003] The techniques disclosed in Patent Documents 1 and 2 both involve laminating a new SiC layer on a damaged surface of a SiC component damaged by use by CVD (Chemical Vapor Deposition), and then machining the new SiC layer to obtain the original component shape.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: (Japanese) Patent Publication No. 2012-49220

[0007] Patent Document 2: (Japanese) Patent Publication No. 2017-212427 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] According to the technology disclosed in Patent Documents 1 and 2, it is indeed possible to obtain a regenerated component of the same quality as the SiC component before use. However, in the technology disclosed in Patent Documents 1 and 2, it is necessary to perform various pre-processing steps such as pre-processing and cleaning of the damaged part and masking of the part where the new SiC layer is not stacked before stacking and processing the new SiC layer. Therefore, the cost required for regeneration is high, and it is difficult to show an advantage compared with the manufacturing cost of new products.

[0010] Therefore, an object of the present invention is to provide a method for regenerating a film-formed structure simply and at low cost, and a regenerated film structure produced by the method.

[0011] Technical solutions for solving technical problems

[0012] The regeneration method of the film-forming structure of the present invention for achieving the above-mentioned purpose is characterized in that it includes: a new film-forming layer stacking step, in which the surface opposite to the damaged surface becomes the main forming surface and a new film-forming layer with a thickness greater than the depth of the damage is stacked; an active surface processing step, in which the damaged surface is processed to obtain a desired shape; in the active surface processing step, the damaged portion is processed to a depth that can completely remove the damaged portion.

[0013] Furthermore, in the method for regenerating the film-forming structure having the above-mentioned characteristics, the new film-forming layer lamination step can be performed in a state where the active surfaces of the two film-forming structures are in contact or close to each other. With such characteristics, a new film-forming layer can be laminated on the inactive surfaces of the two film-forming structures at one time.

[0014] In the method for regenerating a film-forming structure having the above characteristics, the film-forming structure can be a SiC component. By using a SiC component having a high manufacturing cost, a good effect can be obtained in reducing the manufacturing cost.

[0015] Furthermore, the regenerated film structure used to achieve the above-mentioned purpose is characterized in that an active surface and an inactive surface are integrally formed on the surface and the inside, and the active surface is obtained by processing to completely remove the damaged portion of the damaged old film-forming layer, and the inactive surface is obtained by forming a new film-forming layer with a thickness greater than the depth of damage to the old film-forming layer.

[0016] Effects of the Invention

[0017] According to the regeneration method of the film-forming structure having the above-mentioned features, the film-forming structure can be regenerated simply and at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a cross-sectional view showing the shape of a focus ring that has been damaged due to use.

[0019] Figure 2 This is a cross-sectional view showing a state where a new SiC layer is formed on the outer periphery of the focus ring.

[0020] Figure 3 This is a cross-sectional view showing a state where a new SiC layer formed on an inactive surface is cut to form a reference surface.

[0021] Figure 4 This is a cross-sectional view showing a state where the focus ring is being regenerated through processing.

[0022] Figure 5 This is a diagram showing a schematic configuration of a CVD film forming apparatus used for forming a new SiC layer.

[0023] Figure 6 This is a flowchart showing a configuration for implementing the regeneration method of the film-forming structure according to the first embodiment.

[0024] Figure 7 It is a cross-sectional view showing the arrangement of a focus ring for carrying out the regeneration method of a film-formed structure according to the second embodiment.

[0025] Figure 8 This is a cross-sectional view showing that a new SiC layer is formed mainly on each inactive surface of a pair of focus rings.

[0026] Fig. 9 This is a diagram showing a specific example of a case where the focus ring is arranged horizontally when the film-formed structure regeneration method according to the second embodiment is implemented.

[0027] Fig.10 This is a diagram showing a specific example of vertically arranging a focus ring when implementing the film-formed structure regeneration method of the second embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, the regeneration method of the film-forming structure of the present invention and the embodiment of the regenerated film structure are described in detail with reference to the accompanying drawings. A clamp is provided in a chamber for semiconductor manufacturing such as plasma etching, and the regeneration method of the film-forming structure of the present embodiment is effectively applied to SiC parts such as the clamp as the main body.

[0029] [First embodiment]

[0030] As an example of a film-forming structure according to an embodiment of the present invention, a focus ring 10 is a SiC component used to support a wafer (not shown) during plasma etching. The focus ring 10 is a support component that is interposed between the lower electrode and the wafer in the chamber during plasma etching. Therefore, the focus ring 10 is provided with at least a countersunk hole (step 12) for placing the wafer and a through hole 14 for allowing an electrostatic chuck to intervene. It should be noted that the shape of the focus ring 10 is not limited, but Figures 1 to 4 In the example shown, it has a so-called donut shape.

[0031] In the focus ring 10 of such a structure, due to the influence of the plasma etching process, the surface (active surface 10a) on which the wafer is placed is eroded by the plasma and damaged (corroded). The damage on the active surface 10a is not uniform, but Figure 1 As shown in the cross-sectional shape of the focus ring damaged in FIG. 1 , the damage to the outer edge of the step 12 that contacts the periphery of the wafer tends to increase. Figure 1 The outer shape indicated by the two-dot chain line in FIG. 1 shows the outer shape of the focus ring 10 before being damaged.

[0032] In this embodiment, refer to Figures 1 to 4 , Figure 5 A method for regenerating a damaged film-forming structure (focusing ring 10) on the active surface 10a in this manner is described. In this embodiment, a new film-forming layer, namely, a SiC layer (hereinafter referred to as a new SiC layer 16) is formed on the surface of the damaged film-forming structure on the active surface 10a by a CVD method, especially a plasma CVD method, thereby achieving regeneration. It should be noted that, for the film-forming method, other CVD methods such as a thermal CVD method and a photo CVD method can be used, but by using a plasma CVD method, high-speed film formation can be achieved.

[0033] Here, in Figure 5 Detailed description is given of the schematic configuration of a CVD film forming apparatus for carrying out the method for regenerating a film-formed structure according to the present embodiment. Figure 5 The CVD film forming apparatus 50 shown in the figure is basically composed of a chamber 52, a raw material gas container 60, and a high-frequency power supply 62. The chamber 52 is provided with a nozzle 54 that ejects the raw material gas in plasma and a stage 56 on which a film-forming object (focus ring 10 in this embodiment) is placed, and a vacuum pump 58 is attached. In addition, valves 52a and 52b are provided on the inlet side (raw material gas supply side) and the outlet side (vacuum pump configuration side) of the chamber, respectively, and the chamber is configured to be able to evacuate a vacuum. It should be noted that a heater 56a for heating the film-forming object is provided on the stage 56.

[0034] The high frequency power source 62 is an element for applying a voltage for plasma-forming the source gas supplied from the source gas container 60 , and is interposed in the matching circuit 64 .

[0035] [New film layer stacking process]

[0036] In the regeneration method of the film formation structure of the embodiment, first, the focus ring 10 as the film formation structure is placed on the mounting table 56 in the chamber 52 of the CVD film formation device 50. At this time, the inactive surface 10b of the focus ring 10 is made to become the main forming surface of the new SiC layer 16. Figure 5 When the focus ring 10 is placed on the stage 56 of the CVD film forming apparatus 50 shown in the figure, the active surface 10a is arranged opposite to the stage 56. This is because it is difficult to form a new SiC layer 16 on the active surface 10a side in contact with the stage 56 by adopting such a placement configuration.

[0037] Next, a new SiC layer 16 is formed on the upper surface of the SiC layer (hereinafter referred to as the old SiC layer 18) constituting the damaged focus ring 10. The stacking thickness d of the new SiC layer 16 is not limited, but is at least equal to the depth s of the damage to the focus ring 10 (see Figure 2Here, the new SiC layer 16 is formed thickest on the upper surface side of the device, that is, on the inactive surface 10b side (S10: see Figure 6 ).

[0038] [Active surface processing process]

[0039] After the new SiC layer 16 is formed on the periphery of the old SiC layer 18, the focus ring 10 is removed from the CVD film forming device 50. The periphery of the removed focus ring 10 is cut or polished to adjust the shape. There is no limitation on the cutting and polishing techniques, but in the case of mechanical processing, after the reference surface is formed, the reference surface is basically used as a base point to determine the size and the cutting amount, and then the cutting and polishing of other surfaces are performed.

[0040] In the case of this embodiment, if Figure 3 As shown in FIG. 1 , the new SiC layer 16 stacked on the inactive surface 10 b is cut or ground to a minimum extent to form a reference surface. Figure 3 The outer shape indicated by the two-dot chain line in FIG. 1 represents the desired outer shape of the focus ring 10 .

[0041] After the reference surface is formed, the outer side surface, the active surface 10a and the inner side surface (through hole 14) are processed to form Figure 4 The new focus ring 10 (regenerated membrane structure) shown in FIG. 1 is preferably processed to a depth (thickness) at which the damaged portion (corroded portion) is completely removed. This is because when the regenerated focus ring 10 is used, powdering caused by the brittle corroded portion can be prevented (S20: see FIG. 1 ). Figure 6 ).

[0042] [Cleaning process]

[0043] After the processing is completed, cleaning is performed to remove impurities and the like attached to the surface of the focus ring 10 due to the processing. On the regenerated focus ring 10, the old SiC layer 18 and the new SiC layer 16 are mixed, but only the old SiC layer 18 remains on the active surface (S30: see Figure 6 ).

[0044] [Effect]

[0045] According to the regeneration method of the film-forming structure having such characteristics, it is not necessary to process and clean the damaged portion of the old film-forming layer (the old SiC layer 18 in the embodiment) before forming a new film-forming layer (the new SiC layer 16 in the embodiment).

[0046] Therefore, processing can be performed only when the shape is formed after the new film layer is formed. Therefore, the regenerated film structure can be obtained simply and at low cost.

[0047] Furthermore, by forming a new film-forming layer, i.e., a new SiC layer 16, on the side of the inactive surface 10b and then performing processing, the film-forming structure (the focus ring 10 in the embodiment) can be regenerated even when the damage is deep and pre-processing is not possible. Conventionally, pre-processing is performed until the damaged part is smoothed by cutting or grinding, but when the thickness of the component after processing is extremely thin, the component is damaged or warped, making pre-processing impossible. However, as in the present embodiment, by performing a step of forming a new film-forming layer (new SiC layer 16) before processing, the component thickness can be ensured even when the damage to the old film-forming layer (old SiC layer 18) is deep, and thus a regenerated film-forming structure (focus ring 10) can be formed.

[0048] Furthermore, the regenerated film structure (focus ring 10 ) formed as described above can maintain the quality as a single film formation structure (a component made of SiC in the present embodiment) and can be manufactured at a lower cost than new manufacturing.

[0049] It should be noted that, in the present embodiment, the CVD method is described as an example of a means for forming the new SiC layer 16. However, a physical vapor deposition method (PVD: Physical Vapor Deposition) such as a vacuum evaporation method or a sputtering method may also be used to form the new SiC layer 16. This is because as long as the new SiC layer 16 can be formed on the inactive surface 10b side of the old SiC layer 18, the regeneration method of the film formation structure of the present invention can be implemented.

[0050] [Second embodiment]

[0051] Next, refer to Figure 7 , Figure 8 A second embodiment of the method for regenerating a film-forming structure of the present invention will be described. It should be noted that the basic steps of the method for regenerating a film-forming structure of this embodiment are the same as those of the method for regenerating a film-forming structure of the first embodiment.

[0052] The method for regenerating a film-forming structure according to the present embodiment is different from the method for regenerating a film-forming structure according to the first embodiment in that a step of forming a new film-forming layer with two film-forming structures as a pair is performed.

[0053] Specifically, the active surfaces 10a, 10a of the two focus rings 10, 10, which are film-forming structures, are arranged to face each other. At this time, the active surfaces 10a, 10a of the two focus rings 10, 10 are in contact or close to each other.

[0054] The pair of focus rings 10, 10 in this state are arranged in the chamber of the CVD film forming apparatus 50 to form a new SiC layer 16. By adopting such a method, Figure 8 As shown, for the new SiC layer 16 formed on each of the focus rings 10 , 10 , the new SiC layer 16 formed on the inactive surface 10 b can be made thicker than the new SiC layer 16 formed on the active surface 10 a .

[0055] The processing step and the cleaning step after the step of laminating the new SiC layer 16 are the same as those in the method for regenerating the film-formed structure of the first embodiment described above, and the processing step and the cleaning step are performed on each focus ring 10 .

[0056] Here, the placement form of the focus ring 10 may be, for example, as follows. First, when the two focus rings 10, 10 are arranged horizontally, as shown in FIG. Fig. 9 As shown in the figure, the stacked focus rings 10 are placed in a state of floating from the mounting table via an outer side surface support jig 70 that can partially support the outer side surface of the focus ring 10 arranged on the lower side. In addition, when the focus ring 10 arranged on the lower side is arranged slightly apart from the focus ring 10 arranged on the upper side, a separation support jig 72 can be arranged between the active surfaces 10a, 10a of the two focus rings 10, 10.

[0057] By adopting such a mounting configuration, the plasmatized source gas enters the inactive surface 10 b of the focus ring 10 disposed at the lower side, and a new SiC layer 16 is formed.

[0058] Furthermore, in the case where the focus ring 10 is arranged vertically, as shown in FIG. Fig.10 As shown, the support can be performed by using a suspension jig 74 having a suspension portion 74a disposed between the two focus rings 10, 10, an inner side surface support portion 74b protruding from the suspension portion 74a toward the side where the focus rings 10, 10 are disposed, and an active surface support portion 74c. According to such a mounting method, a new SiC layer 16 can also be stacked on the inactive surface 10b, 10b side of the two focus rings 10, 10. It should be noted that, when such a mounting form is adopted, a new SiC layer 16 can be formed by heating the focus ring 10 by some method or by using a hot wall CVD film forming device or a film forming method by PVD method.

[0059] Industrial Applicability

[0060] In the above embodiment, as an example of a film-forming structure, a focus ring 10, a fixture used in semiconductor manufacturing, is cited, and the regeneration of the focus ring 10 is described. However, the film-forming structure regeneration method of the present invention can be applied to various film-forming structures with damaged surfaces. For example, in the above embodiment, SiC parts are cited as an example based on the practical distance in terms of cost, but it can also be applied to Si film-forming structures.

[0061] Description of Reference Numerals

[0062] 10…focusing ring, 10a…active surface, 10b…inactive surface, 12…step, 14…through hole, 16…new SiC layer, 18…old SiC layer, 50…CVD film forming device, 52…chamber, 52a, 52b…valve, 54…shower head, 56…stage, 56a…heater, 58…vacuum pump, 60…raw material gas container, 62…high frequency power supply, 64…matching circuit, 70…outer side support jig, 72…separation support fixture, 74…suspension jig, 74a…suspension part, 74b…inner side support part, 74c…active surface support part.

Claims

1. A method for regenerating a film-forming structure, characterized in that: Include: a new film layer lamination step of laminating a new film layer having a thickness equal to or greater than the depth of the damage, with the surface opposite to the damaged surface serving as the main body forming surface; an active surface processing step of processing the damaged surface to obtain a desired shape; In the active surface processing step, processing is performed to a depth at which the damaged portion can be completely removed.

2. The method for regenerating a film-forming structure according to claim 1, characterized in that: The new film-forming layer lamination step is performed in a state where the active surfaces of the two film-forming structures are in contact with or close to each other.

3. The method for regenerating a film-forming structure according to claim 1 or 2, characterized in that: The film-forming structure is a SiC component.

4. A regenerated membrane structure, characterized in that: The active surface and the inactive surface are formed integrally on the surface and the back. The active surface is obtained by completely removing the damaged portion of the damaged old film-forming layer through processing. The inactive surface is obtained by forming a new film layer having a thickness equal to or greater than the depth of damage to the old film layer.

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