Plasma-resistant two-layer coating film structure and its manufacturing method

Abstract

The present invention relates to a two-layer coating film structure formed on the surface of a ceramic or metal substrate to reduce etching by plasma, and a method for producing the same. The present invention provides a plasma-resistant two-layer coating film structure, comprising: a ceramic or metal substrate having pits on its surface; a first coating layer including a ceramic polycrystal having a crystallite size of less than 300 nm, the first coating layer being coated while filling the pits on the substrate surface, and having micro-pits formed on the surface by bonding of ceramic particles, the crystallite size being less than 300 nm; and a second coating layer being a plasma-resistant ceramic film coated on the first coating layer by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), the second coating layer being formed to have a surface roughness (Ra) of 0.2 μm or less without a separate grinding process, and being coated while covering the micro-pits, thereby forming a surface with minimized sites that may become starting points of plasma etching, the second coating layer being crystalline or having a mixture of crystalline and amorphous.

Description

[Technical field]

[0001] The present invention relates to a two-layer coating film structure formed on the surface of a ceramic or metal substrate to reduce etching by plasma, and a method for producing the same. [Background technology]

[0002] In general, it is known that etching of process parts exposed to plasma during semiconductor processing occurs preferentially in locally recessed portions (grooves; hereinafter referred to as pits) on the surface of the process parts, and as etching progresses throughout the entire process parts over time, the etching that started locally spreads over the entire surface of the process parts (Byung-Kuk Lee et al., Non-Patent Document 1).

[0003] In addition, a protective layer against plasma etching has been formed by coating the surfaces of process parts exposed to plasma during semiconductor processing with a substance resistant to plasma (e.g., Y2O3, Junichi Iwasawa et al., Non-Patent Document 2).

[0004] One embodiment of the technology described in Korean Patent Registration No. 10-2213756 (Patent Document 1) is a technology for forming a plasma protective coating layer on the surface of a substrate (process part) by a thermal spray method. However, the coating layer formed by the thermal spray method always contains cracks and pores, and there is a drawback in that plasma etching starts locally from the starting points of such cracks and pores and spreads throughout the entire process part.

[0005] In addition, the technology described in Korean Patent Registration No. 10-0938474 (Patent Document 2) is a technology that realizes a protective layer against plasma etching by forming a coating layer that is crack-free and has almost no pores on the surface of a process part using an aerosol deposition (AD) method.

[0006] The technology described in Korean Patent Publication No. 10-2013-0044170 (Patent Document 3) is a technology that provides cross-shaped scratches having a depth of 1 to 2 μm on the surface of the aerosol deposition layer in addition to the technology described in Patent Document 2 that forms an aerosol deposition layer exposed to plasma.

[0007] Furthermore, the technology described in Korean Patent Publication No. 10-1563130 (Patent Document 4) is a technology that, in addition to the technology described in Patent Document 3, removes valleys and peaks on the surface of a process part, forms a coating film, and then removes the valleys and peaks on the surface of the coating film, resulting in improved plasma resistance compared to the technologies in Patent Documents 1, 2, and 3.

[0008] The coating films (layers) in the above Patent Documents 1 to 4 are commonly produced by applying a powder spray coating technique. Patent Document 1 uses a thermal spraying method, Patent Documents 2 and 3 use an aerosol deposition method, and Patent Document 4 uses a spray coating method other than the thermal spraying method.

[0009] Meanwhile, examples of coating methods other than the thermal spraying method for forming a plasma protective layer include ion-assisted deposition (IAD), plasma reactive deposition (PRD), plasma enhanced CVD, plasma enhanced evaporation, physical vapor deposition (PVD), and plasma immersion ion process (PIIP) technology (Korean Patent Registration No. 10-1309716, Patent Document 5), and other methods for forming a plasma protective layer include plasma-enhanced CVD (PECVD), physical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD) technology (Korean Patent Publication No. 10-2016-0143532, Patent Document 6).

[0010] The techniques of the above Patent Documents 1 to 6 have in common that a plasma protective layer made of a single layer is formed on the surface of a process part exposed to plasma.

[0011] Meanwhile, there is a technology in which an additional coating layer is formed between the surface of the process part exposed to plasma and the plasma protective layer.

[0012] The technology described in Korean Patent Registration No. 10-1108692 (Patent Document 7) is a technology that provides plasma resistance by forming the aerosol deposition layer of Patent Document 2 on the thermal spray coating layer of Patent Document 1. However, a notable point that differentiates this technology from other technologies is that the surface of the coating layer formed on the process part is processed by sandblasting to increase the roughness (average surface roughness of 0.4 to 2.3 μm) so that the aerosol deposition layer can adhere well to the thermal spray coating layer.

[0013] The technology described in Korean Patent Registration No. 10-2182690 (Patent Document 8) is a technology in which a thermal spray coating layer is formed on the surface of a process part exposed to plasma, a part of the surface of the thermal spray coating layer is melted to form a surface melt layer, and a surface complement layer is formed on the melt layer by an aerosol deposition method.

[0014] The technology described in Korean Patent Registration No. 10-1817779 (Patent Document 9) is the same as Patent Document 7 in that it provides plasma resistance by forming the aerosol deposition layer of Patent Document 2 on the thermal spray coating layer of Patent Document 1. However, it differs from Patent Document 7 in that it includes a hydration treatment of the thermal spray coating layer and the aerosol deposition layer.

[0015] The technology described in Korean Patent Publication No. 10-2019-0057753 (Patent Document 10) is the same as Patent Document 7 in that it provides plasma resistance by forming the aerosol deposition layer of Patent Document 2 on the thermal spray coating layer of Patent Document 1, but differs from Patent Document 7 in that the surface of the thermal spray coating layer is polished.

[0016] As described above, Patent Documents 7 to 10 are technologies that aim to reduce plasma etching that begins polarity by forming an aerosol deposition layer (Patent Documents 2 and 3) that reduces pores and cracks in a thermal spray coating film (layer) (Patent Document 1) that has pores and cracks on the surface of a process part exposed to plasma. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] Korean Patent No. 10-2213756 [Patent Document 2] Korean Patent No. 10-0938474 [Patent Document 3] Korean Patent Publication No. 10-2013-0044170 [Patent Document 4] Korean Patent No. 10-1563130 [Patent Document 5] Korean Patent No. 10-1309716 [Patent Document 6] Korean Patent Publication No. 10-2016-0143532 [Patent Document 7] Republic of Korea Patent No. 10-1108692 [Patent Document 8] Korean Patent No. 10-2182690 [Patent Document 9] Korean Patent No. 10-1817779 [Patent Document 10] Korean Patent Publication No. 10-2019-0057753 Summary of the Invention [Problem to be solved by the invention]

[0018] An object of the present invention is to provide a plasma-resistant two-layer coating film structure in which a first coating layer is formed on the surface of a ceramic substrate and a second coating layer is formed on the first coating layer, thereby significantly reducing plasma etching. [Means for solving the problem]

[0019] In order to achieve the above object, the present invention provides a plasma-resistant two-layer coating film structure, comprising: a ceramic or metal substrate having pits on its surface; a first coating layer including a ceramic polycrystal having a crystallite size of less than 300 nm, the first coating layer being coated while filling the pits on the substrate surface, and having micro-pits formed on the surface by bonding of ceramic particles; and a second coating layer being a plasma-resistant ceramic film coated on the first coating layer by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), the second coating layer being formed to have a surface roughness (Ra) of 0.2 μm or less without a separate grinding process, and being coated while covering the micro-pits, thereby forming a surface with minimized sites that may become starting points of plasma etching, and being made of a crystalline material or a mixture of crystalline and amorphous materials.

[0020] Semiconductor process parts may be employed as the substrate.

[0021] The first coating layer is formed from one or more of Al2O3, Y2O3, Tm2O3, Gd2O3, Dy2O3, Er2O3, and Sm2O3, and may be formed to have no cracks, pores of 1 vol% or less, and a layer thickness of 20 μm or less.

[0022] The second coating layer may be formed of a ceramic film containing yttrium (Y) or a ceramic film containing a metal oxide. Specifically, the second coating layer may be formed of any one or more of Y2O3, YF3, YOF, YAG, YAP, and YAM, or any one or more of Tm2O3, Gd2O3, Dy2O3, Er2O3, and Sm2O3, and may be formed to have no pores and a layer thickness of 15 μm or less. The second coating layer may be formed so that its surface hardness (Vicker shardness; Hv) is Hv 500 to Hv 1,500.

[0023] The present invention also provides a method for manufacturing a plasma-resistant two-layer coating film structure, the method including: (a) spraying a ceramic powder onto a ceramic or metal substrate having pits on its surface by a spray coating method other than thermal spraying, thereby forming a first coating layer including a ceramic polycrystal having a crystallite size of less than 300 nm, the first coating layer being coated while filling the pits on the substrate surface and forming micro-pits on the surface due to bonding of ceramic particles; and (b) forming a second coating layer on the first coating layer by one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD) to cover the micro-pits and form a surface with minimized sites that may become starting points for plasma etching, the second coating layer being made of a ceramic film that is crystalline or a mixture of crystalline and amorphous and includes yttrium (Y) or a metal oxide, and having a surface roughness (Ra) of 0.2 μm or less.

[0024] Before the step (a), a step (a-0) of grinding the surface of the base material may be further included, and in the step (a-0), the surface of the base material may be ground so that the surface roughness (Ra) is 0.2 μm or less.

[0025] A step (a-1) of grinding the surface of the first coating layer may be further included between the steps (a) and (b), and in the step (a-1), the surface of the first coating layer may be ground so that the surface roughness (Ra) is 0.2 μm or less.

[0026] After the step (a-1), the method may further include a step (a-2) of increasing the thickness of the first coating layer and a step (a-3) of grinding the surface of the first coating layer having the increased thickness. Similarly, in the step (a-2), the thickness of the first coating layer may be increased by a spray coating method other than thermal spray. In the step (a-3), the surface of the first coating layer having the increased thickness may be ground to have a surface roughness (Ra) of 0.2 μm or less.

[0027] After the step (b), a step (c) of subjecting the two-layer coating film structure to a heat treatment may be further included. Effect of the Invention

[0028] According to the present invention, the following effects can be obtained by forming a plasma-resistant two-layer coating film structure on the surface of a ceramic or metal substrate.

[0029] 1. The plasma resistance of the substrate can be ensured by forming a first coating layer on the surface of a substrate having pits ranging in size from several micrometers (μm) to several tens of micrometers, and then forming a second coating layer made of a plasma-resistant ceramic film on the first coating layer, which has micropits (starting points at which plasma etching can concentrate) that are relatively smaller than the pits on the substrate surface, using a ceramic coating, and thereby having no pits on which plasma etching can concentrate or having significantly reduced pits on which plasma etching can concentrate.

[0030] 2. Semiconductor process parts having a plasma-resistant two-layer coating film structure formed thereon can reduce particle adhesion during processes in which plasma is applied.

[0031] 3. Through the above-mentioned plasma etching and particle reduction, semiconductor manufacturing and processing processes can be carried out continuously and stably, improving production yields.

[0032] 4. It can reduce the defective rate of products after manufacturing and processing such as semiconductors.

[0033] 5. Extended external cleaning intervals for replacement of ceramic or metal substrates. [Brief description of the drawings]

[0034] [Figure 1] 1 is a schematic cross-sectional view of a plasma-resistant two-layer coating film structure according to the present invention. [Diagram 2] FIG. 1 is a schematic cross-sectional view of a single-layer coating film formed along a pit present on the surface of a substrate by a conventional PVD, CVD, or ALD method. [Diagram 3] 1 is a schematic cross-sectional view of a coating film of a conventional thermal spray coating layer and an aerosol deposition layer formed on a surface of a substrate by an aerosol deposition method. [Figure 4] FIG. 2 is a detailed schematic cross-sectional view of the plasma-resistant two-layer coating film structure according to the present invention. [Diagram 5] FIG. 2 is a process flow diagram of a method for producing a plasma-resistant two-layer coating film structure according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] A ceramic or metal substrate having pits on its surface; a first coating layer, which is a ceramic coating film formed on the surface of the substrate without cracks by a spray coating method other than thermal spray, and which is coated while filling pits on the surface of the substrate, and which includes a ceramic polycrystal having a crystallite size of less than 300 nm and fine pits formed on the surface due to bonding of ceramic particles; A plasma-resistant ceramic film is coated on the first coating layer by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), and is formed to have a surface roughness (Ra) of 0.2 μm or less without a separate grinding process, and is coated while covering the micro-pits, thereby forming a surface with minimized areas that may become starting points for plasma etching, and is made of crystalline or a mixture of crystalline and amorphous materials; and A plasma-resistant two-layer coating film structure comprising:

[0036] The technical concept of the present invention is clearly comparable to the above-mentioned Patent Documents 1-10.

[0037] The above-mentioned Patent Document 1 is a thermal spraying method, and the coating layer formed by this technique contains cracks and pores, and plasma etching occurs significantly due to the cracks and pores.

[0038] The aforementioned Patent Documents 2 to 4 aim to achieve plasma resistance with a single layer by powder spray coating rather than thermal spraying. This group of technologies achieves the effect of preventing the formation of pores and cracks in the coating layer, but micro-pits are formed on the surface due to the bonds between powder particles during the coating process. These micro-pits become weak points where plasma etching concentrates, and the width and depth of the pits increase from these points, affecting the base material.

[0039] The aforementioned Patent Documents 5 and 6 are technologies for achieving plasma resistance by forming a single coating layer using a method other than powder spray coating. According to these technologies, dense coating is formed, but since the coating layer is formed as a thin film, the coating layer follows the shape of the pits on the surface of the substrate rather than filling them, and the morphological characteristics of such a coating layer make it vulnerable to plasma.

[0040] The aforementioned Patent Documents 7 to 10 aim to achieve plasma resistance by using a double layer (thermal spray coating layer + aerosol coating layer) by powder spray coating. The surface of the aerosol coating layer, which becomes the double coating layer, has the problem of the occurrence of micro-pits explained in the aforementioned Patent Documents 2 to 4, and the thermal spray coating layer, which becomes the single coating layer, inevitably has cracks and pores, so that the single coating layer cannot adequately prevent the spread of plasma etching starting from the micro-pits formed on the surface of the double coating layer.

[0041] In contrast, in the plasma-resistant two-layer coating film structure of the present invention, the first coating layer is formed by powder spray coating excluding thermal spray, and the second coating layer is formed by a method such as chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), etc., which forms a coating layer that is relatively denser (e.g., atomic unit stacking) than the first coating layer.

[0042] In the present invention, even if there are relatively large pits on the surface of the substrate, ranging in size from several micrometers (μm) to several tens of micrometers, the first coating layer fills the pits on the surface of the substrate, and the micro-pits formed on the surface of the first coating layer are covered by the densely coated second coating layer, thereby minimizing areas where plasma etching concentrates on the surface of the second coating layer, thereby achieving significantly superior plasma etching resistance compared to conventional technologies (Patent Documents 1 to 10).

[0043] The invention will now be described with reference to the accompanying drawings.

[0044] I. Plasma-resistant two-layer coating film structure The present invention provides a plasma-resistant two-layer coating film structure, comprising: a ceramic or metal substrate having pits on its surface; a first coating layer including a ceramic polycrystal having a crystallite size of less than 300 nm, the first coating layer being coated while filling the pits on the substrate surface, and having micro-pits formed on the surface by bonding of ceramic particles, the crystallite size being less than 300 nm; and a second coating layer being coated on the first coating layer by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), the second coating layer being formed to have a surface roughness (Ra) of 0.2 μm or less without a separate grinding process, and being coated while covering the micro-pits, thereby forming a surface with minimized areas that may become starting points of plasma etching, the second coating layer being crystalline or having a mixture of crystalline and amorphous.

[0045] The plasma-resistant two-layer coating film structure of the present invention may be produced according to the method described below in "II. Production method of plasma-resistant two-layer coating film structure."

[0046] The structure of the present invention, as shown in FIG. 1, consists of a first coating layer and a second coating layer laminated in sequence on a ceramic or metal substrate.

[0047] As shown in FIG. 1, the plasma-resistant two-layer coating film structure provided by the present invention is a coating film structure composed of a first coating layer formed on the surface of a ceramic or metal substrate, and a second coating layer formed on the first coating layer.

[0048] 1. First coating layer The first coating layer is a ceramic film that includes ceramic polycrystals having a crystallite size of less than 300 nm.

[0049] The fact that the first coating layer includes a ceramic polycrystalline body means that the first coating layer may be entirely made of a polycrystalline body, or may contain a portion of amorphous material.

[0050] In other words, when the first coating layer is formed using the powder spray coating method, powder particles collide with the substrate at high speed (or ultra-high speed), or the powder particles are crushed due to collisions with each other, causing the particles to lose their crystallinity and change to an amorphous phase, which may result in some amorphous material being present between the crystals.

[0051] In addition, unlike a coating film formed by melting ceramic powder particles using a thermal spray coating method, the polycrystalline body of the first coating layer is characterized in that the ceramic powder particles are crushed due to collision between the substrate and the particles, and are formed as crystallites with a size of less than 300 nm.

[0052] The crystallite size of the polycrystals can be confirmed from a transmission electron microscopy (TEM) photograph, and the components of the ceramic film can be analyzed using an energy dispersive X-ray (EDX) analysis.

[0053] The first coating layer may be formed of one or more of Al2O3, Y2O3, Tm2O3, Gd2O3, Dy2O3, Er2O3, and Sm2O3.

[0054] Meanwhile, unlike the powder spray coating method, a ceramic film formed by physical vapor deposition (PVD) or chemical vapor deposition (CVD) or atomic layer deposition (ALD) method is generally formed along pits on the surface of a substrate, as shown in FIG. 2.

[0055] However, the first coating layer is formed while filling pits on the surface of the substrate as shown in Fig. 4. However, micro-pits may be formed on the surface of the first coating layer during the process of bonding ceramic powder particles to form the coating layer.

[0056] The first coating layer according to the present invention is characterized in that it has a thickness of 20 μm or less. The thickness of the first coating layer can be confirmed using a scanning electron microscope (SEM) photograph.

[0057] Meanwhile, as shown in Figure 3, a thermal spray coating layer on a substrate surface inevitably has cracks due to the method of melting powder and spraying coating, but the first coating layer on the substrate surface according to the present invention is characterized by being crack-free, unlike a thermal spray coating layer. The presence or absence of cracks in the coating layer can be confirmed using a scanning electron microscope (SEM) photograph.

[0058] Furthermore, the first coating layer is characterized in that the porosity is 1 vol% or less. There are no pores, or even if there are pores, the porosity is 1 vol% or less. The presence or absence of pores in the first coating layer can be confirmed from SEM or TEM photographs.

[0059] 2. Second Coating Layer The second coating layer is a plasma-resistant ceramic film formed on the first coating layer, and may be made of a ceramic film containing yttrium (Y) or a ceramic film containing a metal oxide to ensure plasma resistance.

[0060] Ceramic films containing yttrium (Y) include Y2O3, YF3, yttrium oxyfluoride (YOF), yttrium aluminium (YAG, Y3Al5O 12 ), yttrium aluminum perovskite (YAP, YAlO3), and yttrium aluminum monoclinic (YAM, Y4Al2O9).

[0061] The ceramic film containing a metal oxide may be formed from at least one of Tm2O3, Gd2O3, Dy2O3, Er2O3, and Sm2O3.

[0062] The second coating layer is entirely crystalline or has a mixture of crystalline and amorphous. When the ceramic film is formed by a method such as CVD, PVD, or ALD, a mixture of crystalline and amorphous can be observed, and when a film in such a state is subjected to a heat treatment, the film becomes entirely crystalline. The presence or absence of crystalline or a mixture of crystalline and amorphous in the ceramic film of the second coating layer can be confirmed from a TEM photograph or a selected area (electron) diffraction (SAD, SAED) pattern.

[0063] As described above, the first coating layer is applied while filling the pits on the surface of the substrate, resulting in the formation of micro-pits on the surface. However, the micro-pits in the first coating layer are covered by the second coating layer, minimizing the locations that can become the starting points of plasma etching, thereby improving plasma resistance.

[0064] The second coating layer is formed to a thickness of 15 μm or less, and has a surface hardness (Vicker shardness; Hv) of Hv 500 to Hv 1,500. The greater the surface hardness, the more improved the plasma resistance (plasma etching resistance). The second coating layer is characterized by having a surface roughness (Ra) of 0.2 μm or less.

[0065] II. Manufacturing method for plasma-resistant two-layer coating film structure The present invention also provides a method for manufacturing a plasma-resistant two-layer coating film structure, the method including: (a) spraying a ceramic powder onto a ceramic or metal substrate having pits on its surface by a spray coating method other than thermal spraying, thereby coating the substrate while filling the pits on the substrate surface, and forming a first coating layer including a ceramic polycrystal having a crystallite size of less than 300 nm, and forming micro-pits on the surface due to bonding of ceramic particles; and (b) forming a second coating layer on the first coating layer by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), covering the micro-pits to form a surface in which the number of sites that may become the starting point of plasma etching is minimized, the second coating layer being made of a ceramic film that is crystalline or a mixture of crystalline and amorphous and includes yttrium (Y) or a metal oxide, and having a surface roughness (Ra) of 0.2 μm or less.

[0066] In the above section "I. Plasma-resistant two-layer coating film structure", the characteristics of the plasma-resistant two-layer coating film structure provided by the present invention and the phenomena and effects exhibited by the characteristics were described. The manufacturing method of the plasma-resistant two-layer coating film structure will be described below.

[0067] The plasma-resistant two-layer coating film structure according to the present invention is manufactured by forming a first coating layer and a second coating layer according to the process sequence shown in FIG.

[0068] The step (a) is a step of spray coating a ceramic powder onto a ceramic or metal substrate to form a first coating layer. As mentioned above, the substrate can be a semiconductor processing part.

[0069] In the step (a), the first coating layer may be formed by applying a spray coating method (such as an ALD method) other than thermal spray.

[0070] Before the step (a), a step (a-0) of grinding the surface of the substrate may be further included to reduce the depth of the pits on the surface of the substrate, and in the step (a-0), the surface of the substrate may be ground so that the surface roughness (Ra) is 0.2 μm or less.

[0071] Between the steps (a) and (b), a step (a-1) of grinding the surface of the first coating layer may be further included to further reduce the depth and width of the surface micro-pits of the first coating layer. In the step (a-1), the surface of the first coating layer may also be ground so that the surface roughness (Ra) is 0.2 μm or less.

[0072] After the step (a-1), the method may further include a step (a-2) of increasing the thickness of the first coating layer and a step (a-3) of grinding the surface of the first coating layer with the increased thickness. Similarly, in the step (a-2), the thickness of the first coating layer may be increased by a spray coating method other than thermal spray, and in the step (a-3), the surface of the first coating layer with the increased thickness may be ground to a surface roughness (Ra) of 0.2 μm or less to minimize the depth of micro-pits on the surface of the first coating layer with the increased thickness.

[0073] The step (b) is a step of forming a second coating layer made of a ceramic film containing yttrium (Y) or a ceramic film containing a metal oxide on the first coating layer by a spray coating method other than thermal spray coating.

[0074] In step (b), the second coating layer may be formed by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), and the second coating layer may be formed to have a surface roughness (Ra) of 0.2 μm or less without a separate grinding process.

[0075] According to step (b), the second coating layer can be formed to a thickness of 15 μm or less and a surface hardness (Vicker shardness; Hv) of Hv 500 to Hv 1,500. The higher the surface hardness, the more improved the plasma resistance (plasma etching resistance).

[0076] The present invention can be applied to various modifications and variations without departing from the spirit of the present invention, and can be used in various fields. Therefore, the claims of the present invention cover the modifications and variations that fall within the true scope of the previous invention. [Industrial Applicability]

[0077] The plasma-resistant two-layer coating film structure and its manufacturing method provided by the present invention are applicable to the semiconductor industry.

Claims

1. A ceramic or metal substrate having pits on its surface; a first coating layer comprising a ceramic polycrystal having a crystallite size of less than 300 nm, the first coating layer being a ceramic coating film formed on the surface of the substrate without cracks by a spray coating method other than thermal spraying, the first coating layer being coated while filling pits on the surface of the substrate, and having micropits formed on the surface due to bonding of ceramic particles; a plasma-resistant ceramic film coated on the first coating layer by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), the second coating layer being formed to have a surface roughness (Ra) of 0.2 μm or less without a separate grinding process, and being coated while covering the micro-pits, thereby forming a surface in which the number of sites that may become the starting point of plasma etching is minimized, and being made of crystalline or a mixture of crystalline and amorphous; A plasma-resistant two-layer coating film structure comprising:

2. 2. The plasma-resistant two-layer coating film structure according to claim 1, wherein the substrate is a semiconductor processing part.

3. The first coating layer is Al ２ O ３ , Y ２ O ３ , Tm ２ O ３ , Gd ２ O ３ , Dy ２ O ３ , Er ２ O ３ , Sm ２ O ３ 2. The plasma-resistant two-layer coating film structure according to claim 1, which is formed from at least one of the following:

4. 2. The plasma-resistant two-layer coating film structure according to claim 1, wherein the first coating layer is free of cracks.

5. 2. The plasma-resistant two-layer coating film structure according to claim 1, wherein the first coating layer contains pores at a concentration of 1 vol % or less.

6. 2. The plasma-resistant two-layer coating film structure according to claim 1, wherein the first coating layer has a thickness of 20 [mu]m or less.

7. 2. The plasma-resistant two-layer coating film structure according to claim 1, wherein the second coating layer is a ceramic film containing yttrium (Y) or a ceramic film containing a metal oxide.

8. The second coating layer is ２ O ３ , Y.F. ３ 2. The plasma-resistant two-layer coating film structure according to claim 1, which is made of at least one of the following: YOF, YAG, YAP, and YAM.

9. The second coating layer has a Tm ２ O ３ , Gd ２ O ３ , Dy ２ O ３ , Er ２ O ３ , Sm ２ O ３ 2. The plasma-resistant two-layer coating film structure according to claim 1, which is formed from at least one of the following:

10. 10. The plasma-resistant two-layer coating film structure according to claim 1, wherein the second coating layer is free of pores.

11. The plasma-resistant two-layer coating film structure according to claim 10, wherein the second coating layer has a thickness of 15 μm or less.

12. The plasma-resistant two-layer coating film structure according to claim 10, wherein the second coating layer has a surface hardness (Vickers hardness; Hv) of Hv 500 to Hv 1,500.

13. (a) spraying a ceramic powder onto a ceramic or metal substrate having pits on its surface by a spray coating method other than thermal spraying, coating the substrate while filling the pits on the substrate surface, forming micro-pits on the substrate surface due to bonding of ceramic particles, and forming a first coating layer including a ceramic polycrystalline body having a crystallite size of less than 300 nm; (b) forming a second coating layer on the first coating layer by any one of chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD) to form a surface with minimized areas that may become starting points for plasma etching, the second coating layer being made of a ceramic film containing yttrium (Y) or a metal oxide, and having a surface roughness (Ra) of 0.2 μm or less, and being made of crystalline or a mixture of crystalline and amorphous materials; A method for producing a plasma-resistant two-layer coating film structure, comprising:

14. The method for producing a plasma-resistant two-layer coating film structure according to claim 13, further comprising a step (a-0) of grinding the surface of the substrate before the step (a).

15. The method for producing a plasma-resistant two-layer coating film structure according to claim 14, characterized in that in the step (a-0), the surface of the substrate is ground so that the surface roughness (Ra) is 0.2 μm or less.

16. The method for producing a plasma-resistant two-layer coating film structure according to claim 13, further comprising a step (a-1) of grinding the surface of the first coating layer between the steps (a) and (b).

17. The method for producing a plasma-resistant two-layer coating film structure according to claim 16, characterized in that in the step (a-1), the surface of the first coating layer is ground so that the surface roughness (Ra) is 0.2 μm or less.

18. After the step (a-1), (a-2) spraying ceramic powder by a spray coating method other than thermal spray to increase the thickness of the first coating layer; A step (a-3) of grinding the surface of the first coating layer of increased thickness; The method for producing a plasma-resistant two-layer coating film structure according to claim 17, further comprising:

19. The method for manufacturing a plasma-resistant two-layer coating film structure according to claim 18, wherein in the step (a-3), the surface of the first coating layer having the increased thickness is ground to have a surface roughness (Ra) of 0.2 μm or less.

20. The method for producing a plasma-resistant two-layer coating film structure according to claim 13, further comprising a step (c) of subjecting the two-layer coating film structure to a heat treatment after the step (b).

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