Structural member

Abstract

Provided is a structural member capable of preventing the surface of a protective film from being polished at or above necessary during manufacturing. A structural member (10) is provided with: a base material (100); and a protective film (200) that covers the surface (110) of the substrate (100). Particles (300) having a higher hardness than the protective film (200) are dispersed inside the protective film (200).

Description

Technical Field

[0001] The invention relates to a structural member. Background Art

[0002] Structural components having a protective film on the surface of a substrate are used in various fields such as semiconductor manufacturing equipment. For example, as described in Patent Document 1 below, in a semiconductor manufacturing equipment, a protective film for protecting the substrate from plasma is formed on the surface of the substrate constituting the inner wall of a chamber.

[0003] Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2007-321183 Summary of the invention

[0004] For example, a protective film is formed on the surface of the substrate by a film forming method such as an aerosol deposition method. Afterwards, the surface of the protective film is ground to adjust its flatness. At this time, stress caused by grinding sometimes remains in the surface portion of the protective film. Such residual stress may become the cause of reduced durability of the protective film or the cause of particle generation. Therefore, after grinding the surface of the protective film, it is preferred to perform fine grinding on the surface portion of the surface to release the residual stress in advance. The "fine grinding" mentioned here refers to grinding the surface of the protective film without generating residual stress as much as possible, for example, using a softer component such as a grinding cloth or performing chemical etching.

[0005] The thickness of the surface layer to be removed by fine grinding is very thin, about 100 nm at most. If a thickness greater than this is removed, the durability of the protective film will be reduced in vain, so it is not preferred. Therefore, when fine grinding is performed, it is necessary to grind while confirming how much thickness is removed from the surface of the protective film each time.

[0006] As a method for confirming the thickness to be removed, for example, a method of measuring the thickness of the entire protective film each time using a reflection spectroscopic film thickness meter and calculating its change can be considered. However, it is difficult to use a reflection spectroscopic film thickness meter to accurately measure a small change of about 100 nm or less. Therefore, when fine grinding is performed, it is necessary to remove more of the surface layer of the protective film than the necessary minimum thickness to be removed.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to provide a structural member capable of preventing the surface of a protective film from being polished more than necessary during manufacture.

[0008] In order to solve the above problems, the structural member of the present invention comprises: a substrate; and a protective film covering the surface of the substrate. High-hardness particles having a higher hardness than the protective film are dispersed and arranged inside the protective film.

[0009] If the protective film thus constructed is finely ground, the high hardness particles exposed on the surface of the protective film are hardly removed but remain, so that the high hardness particles protrude from the surface of the protective film. At this time, the amount of protective film removed is approximately equal to the amount of high hardness particles protruding.

[0010] If a measuring device such as an electric micrometer is used, the protrusion amount of the high hardness particles can be measured relatively easily and with high accuracy. Therefore, by performing fine grinding while measuring the protrusion amount, i.e., the removal amount, each time, it is possible to remove the necessary surface layer portion. In other words, it is possible to prevent the surface of the protective film from being ground more than necessary.

[0011] After the structural member is installed in an etching device, etc. and the surface of the protective film is exposed to plasma for a certain period of time and aged, in order to reuse the structural member, the surface can be re-grinded to remove the aged part. In other words, the surface of the aged protective film can be refurbished. In the structural member of the above-mentioned structure, the high hardness particles are not only dispersed on the surface of the protective film, but also dispersed throughout the interior. Therefore, when refurbishing, fine grinding is performed while measuring the protruding amount of the high hardness particles, as described above, so that only the protective film of appropriate thickness can be removed again.

[0012] According to the present invention, there is provided a structural member capable of preventing the surface of a protective film from being polished more than necessary during production. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram schematically showing a cross section of a structural member according to the present embodiment. Figure 2 It is a diagram showing a cross section of a protective film in the structural member according to the present embodiment. Figure 3 It is a diagram for explaining the method of manufacturing the structural member according to the present embodiment. Figure 4 It is a diagram for explaining the method of manufacturing the structural member according to the present embodiment. Explanation of symbols 10-structural component; 100-substrate; 110-surface; 200-protective film; 300-particles. DETAILED DESCRIPTION

[0014] Hereinafter, the present embodiment will be described with reference to the drawings. In order to facilitate the description, the same components in the drawings are denoted by the same reference numerals as much as possible, and repeated descriptions are omitted.

[0015] The structural member 10 according to the present embodiment is used as an inner wall of a processing chamber in a semiconductor manufacturing apparatus (not shown) such as a plasma etching apparatus. The use of the structural member 10 is only an example and is not limited to semiconductor manufacturing apparatuses.

[0016] like Figure 1 As shown, the structural member 10 includes a substrate 100 and a protective film 200. In a plasma etching apparatus or the like, a surface 210 of the protective film 200 is exposed to the space in the chamber. The protective film 200 is provided for the purpose of protecting the surface 110 of the substrate 100 from plasma.

[0017] The substrate 100 is a member that occupies substantially the entirety of the structural member 10. In the present embodiment, the substrate 100 is a ceramic sintered body containing high-purity aluminum oxide (Al2O3), but it may be a ceramic of a different type or a member other than ceramic (e.g., a metal member). In addition, although the surface 110 of the substrate 100 is a flat surface in the present embodiment, the surface 110 may also have a concave-convex portion or an inclined portion.

[0018] As described above, the protective film 200 is a film formed to protect the substrate 100 from plasma. The protective film 200 is formed to cover the entire surface 110 of the substrate 100. In the present embodiment, the protective film 200 is formed as a film containing polycrystalline yttrium oxide (Y2O3) as a main component, but it can also be a ceramic film composed of a material different from this. The thickness of the protective film 200 is appropriately set according to the length of the period for which durability is required to be maintained. In the present embodiment, the thickness of the protective film 200 is 10μm.

[0019] The protective film 200 of this embodiment is formed on the surface 110 of the fired substrate 100 by an aerosol deposition method. As is well known, in the aerosol deposition method, the material of the protective film 200, i.e., tiny particles, are dispersed in a gas to form an "aerosol", and then sprayed from a nozzle to the surface 110 to cause a collision. On the surface 110, the tiny particles are deformed and broken due to the impact of the collision, so that the tiny particles are combined with each other and accumulated little by little as the protective film 200. The protective film 200 can also be a film formed by other film forming methods.

[0020] Figure 2, a cross section of the protective film 200 is depicted in more detail. As shown in the figure, a plurality of particles 300 are dispersed and arranged inside the protective film 200. In the present embodiment, the particles 300 are formed of a material having aluminum oxide as a main component. Therefore, the hardness of the particles 300 (aluminum oxide) is higher than the hardness of the protective film 200 (yttrium oxide) surrounding them. Each particle 300 corresponds to a "high hardness particle" in the present embodiment.

[0021] As long as the hardness of the particle 300 is higher than the hardness of the protective film 200, it can also be formed of other materials. As in the present embodiment, when the main component of the protective film 200 is yttrium oxide, for example, the particle 300 can also be formed of a material containing yttrium, aluminum and garnet (YAG). By using such a composite material, the mechanical strength of the protective film 200 including the particle 300 can also be improved.

[0022] The arrangement density of particles 300, i.e., the number of particles 300 contained in a unit volume of protective film 200, is substantially uniform throughout protective film 200. Although most particles 300 are entirely buried in protective film 200, some particles 300 protrude outward from surface 210 of protective film 200.

[0023] Hereinafter, the distance from the surface 210 of the protective film 200 to the top of the protruding particle 300 (the distance in the direction perpendicular to the surface 210) is defined as the "protrusion amount H" of the particle 300. In the present embodiment, the protrusion amounts H of the respective particles 300 protruding from the surface 210 are equal. The method for making the respective protrusion amounts H equal will be described later. The protrusion amounts H may be approximately equal, and may deviate from the average value by about 10%, for example.

[0024] like Figure 2 As shown, the tips 310 of the particles 300 protruding from the surface 210 of the protective film 200 are parallel flat surfaces with respect to the surface 210 .

[0025] Reference Figure 3 and Figure 4 A method for manufacturing the structural member 10 is described. Figure 3 As shown in (A), first, a substrate 100 is prepared. In order to stably form the protective film 200, it is preferable to adjust the surface roughness of the surface 110 of the substrate 100 in advance.

[0026] Next, if Figure 3 As shown in (B), the protective film 200 is formed so as to cover the surface 110 of the substrate 100. As described above, the protective film 200 of this embodiment is formed by the aerosol deposition method.

[0027] In this embodiment, the particles 300, which are the material of the protective film 200, are mixed in a predetermined ratio in advance and mixed thoroughly so that they are evenly distributed. The thus obtained mixture of particles is dispersed in a gas to form an "aerosol", and then sprayed from a nozzle toward the surface 110 to cause collision. Thus, at the end of the film formation by the aerosol deposition method, as shown in FIG. Figure 4 As shown in (A), the particles 300 are dispersed in the protective film 200. At this point, there are almost no particles 300 protruding from the surface 210A of the protective film 200. The entire surface 210A is flat, and all the particles 300 are buried therein.

[0028] Next, Figure 4 The entire surface 210A of (A) is polished to adjust its flatness. Figure 4 (B) schematically shows the state after grinding. Figure 4 (A) surface 210A is ground to produce a new surface also referred to as "surface 210B". From surface 210A to surface 210B, the amount of protective film 200 removed is about 1.0 μm to 2.5 μm. In this grinding, a grindstone made of diamond is used. Therefore, the particles 300 located near the surface of the protective film 200 are ground together with the protective film 200, and the upper end in the figure becomes a flat surface. This flat surface is formed. Figure 2 The top 310 part. Figure 4 At the moment (B), the top 310 and the surface 210A are located on the same plane.

[0029] In order to distinguish it from the fine grinding to be described below, Figure 4 The above-mentioned grinding performed in the state of (B) is also called "rough grinding". As mentioned above, since the removal amount of the protective film 200 in the rough grinding is relatively large, about 1.0μm to 2.5μm, it can be measured by a reflection spectroscopic film thickness meter. Rough grinding is performed while measuring the removal amount each time, and the rough grinding can be ended when the removal amount reaches the preset target value. In addition, the grindstone used for rough grinding can be diamond as mentioned above, but it can also be SiC or CBN (Cubic Boron Nitride), etc.

[0030] During the rough grinding, the protective film 200 is largely eliminated, so there will be residual stress on the surface 210B after grinding. Such residual stress may become the cause of reduced durability of the protective film 200 or the cause of particle generation. Therefore, in order to release the residual stress on the surface 210B, fine grinding is performed after the rough grinding. "Fine grinding" means that the surface 210B of the protective film 200 is ground without generating residual stress as much as possible, for example, using a softer member such as a grinding cloth or performing chemical etching.

[0031] The thickness of the surface layer to be removed by fine grinding is very thin, about 100 nm at most. If a thickness greater than this is removed, the durability of the protective film 200 will be reduced in vain, so it is not preferred. Therefore, when fine grinding is performed, it is necessary to grind while confirming how much thickness is removed from the surface 210B of the protective film 200 each time.

[0032] As a method for confirming the thickness to be removed, for example, a method of measuring the thickness of the entire protective film 200 each time using a reflection spectroscopic film thickness meter and calculating the amount of change can be considered. However, it is difficult to measure a small change of about 100 nm or less with high accuracy using a reflection spectroscopic film thickness meter. Therefore, when fine grinding is performed in the conventional structure, the surface layer of the protective film 200 has to be removed more than the necessary minimum thickness to be removed.

[0033] Therefore, in the present embodiment, particles 300 are dispersed and arranged inside protective film 200 as described above, and thus the removal amount can be easily measured. Figure 4 In (C), the state of the protective film 200 during fine grinding is schematically shown. When fine grinding is performed, the surface of the protective film 200 is removed little by little. Figure 4 The surface 210B of (B) gradually moves toward the substrate 100 side ( Figure 4 The following will be from Figure 4 The surface in which the state (B) gradually recedes is also expressed as "surface 210C".

[0034] On the other hand, the particles 300 have a higher hardness than the protective film 200, and therefore are hardly removed even by fine grinding, but remain in a state of substantially maintaining the original shape. Figure 4 As shown in (C), particles 300 having flat tops 310 are all in a state of protruding outward from surface 210C. The protrusion amount H0 of particles 300 from surface 210C is approximately equal to the thickness of protective film 200 removed so far (the above-mentioned removal amount).

[0035] If a measuring device such as an electric micrometer is used, the protrusion amount H0 of the particle 300 can be measured relatively easily and with high accuracy. Therefore, if fine grinding is performed while measuring the protrusion amount H0, that is, the amount of removal of the protective film 200 each time, only the necessary surface layer can be removed. In other words, it is possible to prevent the surface 210 of the protective film 200 from being ground more than necessary. When the protrusion amount H0 of the particle 300 is equal to the pre-set target value of the removal amount, the fine grinding can be ended. At this time, the surface 210C becomes Figure 2 The protrusion amount H0 at this time becomes Figure 2 The protrusion H.

[0036] During fine grinding, tips 310 of particles 300 protruding from surface 210C of protective film 200 become flat surfaces parallel to surface 210C. Therefore, protrusion amount H0 can be easily and accurately measured using an electric micrometer or the like.

[0037] Furthermore, the protrusion amount H0 of the particle 300 can be directly measured using an electric micrometer or the like, or can be estimated or calculated by other methods. For example, during fine grinding, the photographed surface 210C can be looked down at to estimate or calculate the protrusion amount H0 of the particle 300 based on the size of each particle 300 in the obtained image.

[0038] against Figure 4 The entire surface 210B in (B) is finely ground evenly. Therefore, the protrusion amount H0 of the particle 300, that is, the amount of removal of the protective film 200, is roughly equal throughout. In order to further equalize the removal amount of the protective film 200, in multiple locations of the surface 210C, the protrusion amount H0, that is, the amount of removal of the protective film 200, can be individually measured, and local fine grinding can be performed as needed.

[0039] like Figure 4 As shown in (C), the particle 300 is hardly removed during fine grinding, so the measured protrusion amount H0 of the particle 300 can be directly used as the removal amount of the protective film 200. However, depending on the material of the particle 300, the shape change of the particle 300 due to fine grinding may not be ignored. Even in such a case, there is a certain correlation between the measured protrusion amount H0 of the particle 300 and the removal amount of the protective film 200. Therefore, if the correlation is known in advance through experiments, the removal amount can be easily and accurately calculated based on the protrusion amount H0.

[0040] After the structural member 10 is mounted in an etching device or the like and the surface 210 of the protective film 200 is exposed to plasma for a certain period of time and deteriorates, the surface 210 may be re-polished to remove the deteriorated portion in order to reuse the structural member 10. In other words, the surface 210 may be refurbished.

[0041] Particles 300 are dispersed not only on surface 210 of protective film 200 but also throughout the interior thereof. Therefore, when refurbishing, similarly to the above, fine grinding is performed while measuring the protrusion amount H0 of particles 300, thereby removing only a suitable thickness of protective film 200 again.

[0042] Above, the present embodiment has been described with reference to specific examples. However, the present invention is not limited to these specific examples. With regard to these specific examples, as long as they have the characteristics of the present invention, the technology that is appropriately designed and changed by those skilled in the art is also included in the scope of the present invention. The various elements and their configurations, conditions, shapes, etc. possessed by the aforementioned specific examples are not limited to the illustrated contents, but can be appropriately changed. As long as there is no technical contradiction, the various elements possessed by the aforementioned specific examples can be appropriately changed and combined.

Claims

1. A structural member, characterized in that: With: base material; and a protective film covering the surface of the substrate, High-hardness particles having a higher hardness than that of the protective film are dispersed and arranged inside the protective film.

2. The structural member according to claim 1, characterized in that: A plurality of the high-hardness particles protrude from the surface of the protective film.

3. The structural member according to claim 2, characterized in that: The protrusion amounts of the respective high-hardness particles from the surface of the protective film are uniform.

4. The structural member according to claim 3, characterized in that: The tips of the respective high-hardness particles protruding from the surface of the protective film form flat surfaces parallel to the surface of the protective film.

5. The structural member according to claim 1, characterized in that: The protective film contains yttrium oxide, and the high-hardness particles contain aluminum oxide.

6. The structural member according to claim 1, characterized in that: The protective film contains yttrium oxide, and the high-hardness particles contain yttrium, aluminum, and garnet.

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