JP2007277620A - Method for depositing spray deposit film on brittle base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for depositing a spray deposit film on a brittle base material capable of enhancing the adhesive force of a plasma-resistant spray deposit film by using a means for suppressing warp or breakage of the base material, and easily coarsening the surface of the base material consisting of ceramic or the like at low cost. <P>SOLUTION: A surface of a base material consisting of a brittle material such as a ceramic, a glass or a quartz is coarsened by the micro-blasting using a masking material or a mesh, and a spray deposit film is deposited on the surface of the base material by a plasma thermal spraying method. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for forming a sprayed film on a base material of a member made of a brittle material constituting the inside of a plasma processing apparatus, an etcher for semiconductor / liquid crystal production, a CVD apparatus, or the like.

In recent years, plasma processes using highly reactive halogen-based corrosive gases such as fluorine and chlorine are mainly used in etching processes, CVD film forming processes, ashing processes for removing resists, and the like in semiconductor manufacturing.
Conventionally, members made of silicon, quartz glass, or silicon carbide have been frequently used in semiconductor manufacturing apparatuses. However, these members are significantly corroded by fluorine-based gas, so that they are exposed to the halogen plasma as described above. High-purity alumina, aluminum nitride, and ceramics such as yttria and YAG have come to be used.

However, the ceramic member as described above is expensive, and it is relatively difficult to process a complicated shape or a large size.
For this reason, as a method for producing a plasma-resistant member at a relatively low cost, a method is adopted in which a film having excellent plasma resistance is formed on the surface of a substrate made of ceramics or metal by a thermal spraying method.

In the thermal spraying method, the surface of the substrate is usually subjected to a surface roughening treatment in order to obtain a sufficient adhesion of the thermal spray coating before the thermal spraying treatment.
In general, the roughening treatment of a brittle material such as ceramics is performed by mechanical means such as sandblasting or chemical means such as etching with a chemical solution such as acid (for example, see Patent Document 1).
JP 2003-171190 A

However, the sandblasting process has been difficult to obtain a degree of roughness that allows the concave portions to expand and a sufficient adhesion of the sprayed film to be obtained. In particular, the roughness of the ceramic substrate surface depends on the crystal grain size of the ceramic particles, and as the particle size increases, the strength of the substrate decreases, so the average surface roughness Ra is actually limited to about 5 μm. It was.
In addition, in order to obtain sufficient roughness, it is necessary to increase the particle size of the blasting material used to some extent, and the blasting pressure also increases. In particular, in a brittle material with low strength such as quartz, the base material may be broken.

  In addition, roughening by chemical means such as etching can improve the adhesion of the sprayed film, but it is accompanied by dangers due to the use of chemicals such as acids and difficulty in control, and at a high cost. Had the problem of being.

  The present invention has been made in order to solve the above technical problem, suppresses warpage and breakage of the base material, and at low cost and easily provides a rough surface of the base material made of ceramics or the like. It is an object of the present invention to provide a method for forming a sprayed coating on a brittle material substrate, which can improve the adhesion of the plasma-resistant sprayed coating using a means for converting into a plasma.

In the method for forming a sprayed film on a brittle material substrate according to the present invention, the substrate surface made of the brittle material is roughened by microblasting using a masking material or a mesh, and then the plasma spraying method is applied to the substrate surface. A thermal spray film is formed by the method.
According to the above method, since a patterned concavo-convex structure can be formed on the surface of a base material made of a brittle material, the base material surface can be easily processed to a desired roughness and formed thereon. The adhesion of the sprayed film can be increased.

It is preferable that unevenness is repeatedly present on the roughened substrate surface, and the average level difference of the unevenness is 5 μm or more.
By having the above irregularities, sufficient adhesion of the sprayed film to the substrate surface can be obtained.
The step here is a distance between a straight line connecting the highest points of the convex portions on both sides of one concave portion of the concave and convex portions and the lowest portion of the concave portion, and an average value of each step is an average step.

  Further, according to the above method, the roughened substrate can suppress the flatness to 20 μm or less even when the substrate is a thin plate.

The brittle material is preferably any one of ceramic, glass and quartz.
By subjecting these materials to a surface roughening treatment and forming a plasma-resistant sprayed film, a plasma-resistant member having excellent durability can be obtained.

As described above, according to the method for forming a sprayed coating on a brittle material substrate according to the present invention, the surface can be roughened by suppressing warpage and fracture of the substrate with a low-cost and simple method. The adhesion of the sprayed film can be increased.
Therefore, the present invention can be suitably used when forming a sprayed film on a base material of a member made of a brittle material constituting the inside of a plasma processing apparatus, an etcher for semiconductor / liquid crystal manufacturing, a CVD apparatus, and the like. As a result, the durability of the member as described above can be improved. In particular, it is suitable for forming a ceramic sprayed film having high corrosion resistance against a halogen-based corrosive gas or plasma thereof.

Hereinafter, the present invention will be described in more detail.
The method for forming a sprayed film on a brittle material substrate according to the present invention is a method in which a substrate surface made of a brittle material is roughened by microblasting using a masking material or a mesh, and then plasma sprayed onto the substrate surface. To form a sprayed film.
When microblasting is performed without a mask, the entire surface of the base material is roughened, and can only be made to about Ra 0.8 μm.
On the other hand, in the present invention, a patterned concavo-convex structure can be formed on the surface of a base material made of a brittle material by performing microblasting using a masking material or a mesh.
Therefore, the surface of the substrate can be easily processed to a desired roughness, and the adhesion of the sprayed coating formed thereon can be improved.

As the masking material, a material produced in a mesh shape or the like according to a desired rough surface state can be used, and instead of the masking material, a mesh knitted in a mesh shape can be applied to the surface of the base material. Thus, the roughening process can be performed more simply and at a low cost.
The masking material or mesh is preferably made of a material that is not consumed by microblasting. For example, the masking material is preferably a resin film such as an ASA mask, and the mesh is preferably made of commercially available nylon, polyethylene, PET, or the like.

Moreover, it is preferable that the masking material or mesh to be used is about # 40-200.
If the aperture is too large, the repetition of unevenness formed on the surface of the substrate is reduced, and sufficient adhesion of the sprayed film formed thereon cannot be obtained. On the other hand, if the aperture is too small, the blasting material Cannot pass sufficiently, and sufficient roughness of the substrate surface cannot be obtained.

In order to obtain sufficient adhesion of the sprayed film, the roughened surface of the substrate preferably has irregularities regularly and repeatedly, and the average level difference of the irregularities is preferably 5 μm or more.
The surface roughness is preferably from 1.2 μm to 15 μm in average roughness Ra, although it depends on the material of the base material and the sprayed film.

The flatness of the base material by the roughening is preferably 20 μm or less.
Since microblast usually uses particles of about # 600, the flatness of the substrate in the roughening treatment can be suppressed to 20 μm or less, and even when the substrate is a thin plate, deformation of the substrate is possible. A sprayed film can be formed without causing breakage.

In addition, the method according to the present invention is applied to a substrate made of a brittle material such as alumina, zirconia, mullite, SiC, AlN, YAG, yttria, SiN, etc., or a composite thereof, or a composite material thereof, glass, quartz, etc. be able to.
Even in the brittle material substrate as described above, according to the method according to the present invention, as described above, even if it is a thin plate-like substrate, the warp and fracture of the substrate are suppressed, and the desired roughening is achieved. Processing can be performed.

In the present invention, a sprayed film is formed on the surface of the base material roughened as described above.
As a method for forming a sprayed film, there are generally methods such as flame spraying and plasma spraying. In the present invention, it is preferable to form a film by a plasma spraying method.
Since the plasma spraying method uses a plasma flame, it is performed at a higher temperature than the flame spraying method, and a high melting point spraying material such as yttria can be sufficiently melted and collided with the substrate at a high speed. It is possible to obtain a thermal sprayed film that is formed and has better adhesion.

The sprayed film is preferably made of yttria having excellent plasma resistance, but may be a ceramic film made of YAG, alumina, zirconia, or the like.
In particular, a plasma-resistant sprayed film formed on the substrate by a plasma spraying method has advantages such as suppression of plasma resistance reduction due to peeling of the sprayed film and suppression of particle generation during plasma exposure. Therefore, it can be suitably used as a plasma resistant member.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not restrict | limited by the following Example.
[Examples 1 to 4]
The alumina fired body having a diameter of 300 mm and a thickness of 5 mm was masked with a mesh-shaped masking material, and a roughening treatment was performed with microblast (abrasive grains: GC # 600, pressure: 0.2 MPa).
The average level difference of the surface irregularities was measured with a laser microscope, and the flatness was measured with a three-dimensional measuring machine.

Yttria ceramics (average particle size of 10 to 60 μm) was plasma sprayed on the surface of the roughened alumina fired body to form a sprayed film.
With respect to the thermal sprayed film after thermal spraying, the adhesive force was measured by a bond cap method in which a stud pin having an end bonded with an epoxy resin was pulled in the vertical direction.
Ten samples were prepared for each sample, and the average value of the measured values was obtained.

[Example 5]
Instead of the masking material, the mesh was affixed to the surface of the alumina fired body, and other than that, roughening treatment, sprayed film formation and various measurements were performed in the same manner as in Example 1.

[Example 6]
In place of the alumina fired body, quartz was used as a base material, and other than that, roughening treatment, sprayed film formation, and various measurements were performed in the same manner as in Example 5.

[Comparative Example 1]
A surface roughening treatment was performed without a mask, and the other processes were performed in the same manner as in Example 1 to form a sprayed film and perform various measurements.

[Comparative Example 2]
The surface was roughened by blasting (abrasive grain: WA # 70, pressure: 0.3 MPa) without a mask, and other than that, sprayed film formation and various measurements were performed in the same manner as in Example 1. .

[Comparative Example 3]
In place of the alumina fired body, quartz was used as a base material, and other than that, roughening treatment, sprayed film formation, and various measurements were performed in the same manner as in Comparative Example 2.

Table 1 summarizes the results of the above Examples and Comparative Examples.

  As can be seen from Table 1, the surface of the brittle material substrate is roughened by microblasting using a masking material or mesh, thereby suppressing the warpage of the substrate and forming an uneven surface having steps. It was confirmed that the adhesion of the sprayed film can be improved. In particular, when the average level difference was 5 μm or more, it was confirmed that the improvement in adhesion was great.

Claims (4)

  To a brittle material substrate characterized in that a substrate surface made of a brittle material is roughened by microblasting using a masking material or a mesh, and then a sprayed film is formed on the substrate surface by a plasma spraying method. Thermal spray film forming method.   The method for forming a sprayed film on a brittle material substrate according to claim 1, wherein unevenness is repeatedly present on the roughened substrate surface, and an average step of the unevenness is 5 µm or more.   The method of forming a sprayed film on a brittle material substrate according to claim 1 or 2, wherein the flatness of the substrate by the roughening is 20 µm or less.   The method for forming a sprayed film on a brittle material substrate according to any one of claims 1 to 3, wherein the brittle material is one of ceramics, glass, and quartz.