JP2006008474A - Member for semiconductor manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the generation of particles caused by the peeling or leaving of a part of a film forming component sticking/depositing on the surface of a member for a semiconductor manufacturing device. <P>SOLUTION: In the member for the semiconductor manufacturing device arranged at the semiconductor manufacturing device treating a semiconductor wafer, the member for the semiconductor manufacturing device is an alumina base material having a 4-10 μm surface roughness Ra. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a semiconductor manufacturing apparatus member used in a semiconductor manufacturing apparatus for processing a semiconductor wafer.

  In the manufacturing process of a semiconductor device, a semiconductor manufacturing apparatus such as an etching apparatus or a sputtering apparatus that performs fine processing on a semiconductor wafer or a CVD apparatus that forms a film on a semiconductor wafer is used. As these semiconductor manufacturing apparatuses, for example, a helicon wave plasma etching apparatus is known, and an outline of the configuration is shown in FIG.

  In FIG. 6, the etching chamber 1 has an etching gas supply port 2 and a vacuum exhaust port 3, and an antenna 4, an electromagnet 5, and a permanent magnet 6 are installed on the outer periphery thereof. In the processing chamber 1, a lower electrode 8 that supports a semiconductor wafer 7 to be processed is disposed. The antenna 4 is connected to the first high-frequency power source 10 via the first matching network 9, and the lower electrode 8 is connected to the second high-frequency power source 12 via the second matching network 11. Yes. The member for a semiconductor manufacturing apparatus is mainly disposed in the wall member or the chamber of the etching processing chamber 1.

  Etching by this etching apparatus is performed as follows. That is, the semiconductor wafer 7 is placed on the surface of the lower electrode 8 and the inside of the processing chamber 1 is evacuated, and then the etching gas is supplied from the etching gas supply port 2. Next, a high-frequency current having a frequency of 13.56 MHz, for example, is caused to flow from the high-frequency power sources 10 and 12 to the antenna 4 and the lower electrode 8 via the corresponding matching networks 9 and 11. Further, a high-density plasma is generated by causing a required current to flow through the electromagnet 5 and generating a magnetic field in the processing chamber 1. With this plasma energy, the etching gas is decomposed into atomic states, and the film formed on the surface of the semiconductor wafer 8 is etched.

In this type of semiconductor manufacturing apparatus, a chlorine-based gas (for example, boron chloride (BCl) or the like) or a corrosive gas such as a fluorine-based gas (for example, fluorocarbon (CF ₄ )) is used as an etching gas. Accordingly, the plasma resistance of members for semiconductor manufacturing equipment exposed to plasma in a corrosive gas atmosphere, such as the inner wall of the processing chamber 1, the monitoring window, the microwave introduction window, the lower electrode 8, the electrostatic chuck, and the susceptor. Is required.

  The etching means and film forming means using the plasma energy have the following problems. During the film formation process, for example, not only on the film formation surface of the semiconductor wafer, but also on the surface of the processing chamber wall exposed to plasma and the surface of a member for semiconductor manufacturing equipment such as a support for supporting the film formation substrate Particles are attached and deposited incidentally to form a film. There is a phenomenon in which a part of the film forming component adhering / depositing on the surface of the member for semiconductor manufacturing apparatus is peeled off or detached, and small particles (particles) adhere to the film forming surface.

  The reattachment of particles detached from the surface of the semiconductor manufacturing apparatus member results in, for example, interruption of film formation such as a circuit pattern being formed or deterioration in quality, leading to reduction in reliability or yield of semiconductor products. In order to impart this particle detachment preventing ability, the film deposited in the chamber is usually removed by dry cleaning using plasma or chamber maintenance periodically for each process.

  In addition, means for roughening the surface of a semiconductor manufacturing apparatus member has been proposed (Patent Document 1). That is, a method is known in which the surface is roughened by sandblasting or polishing, and the physical bond with the film to be adhered / deposited is strengthened to make it difficult to peel (providing an anchor effect).

  However, the roughening means such as sandblasting not only has a problem of gas releasing property but also cannot provide a sufficient anchor effect, and the problem of particle detachment still remains.

  In addition, a method of forming a plurality of irregularities by mask etching (Patent Document 2), or a method of removing a crushed layer of ceramics by erosion treatment in an acidic etching solution (Patent Document 3) is known. .

JP 2000-191370 A JP 2001-295024 A JP 2003-171189 A

An object of the present invention is to provide a member for a semiconductor manufacturing apparatus in which an anchor effect is easily obtained and the number of particles is reduced.

The present invention is a semiconductor manufacturing apparatus member arranged in a semiconductor manufacturing apparatus for processing a semiconductor wafer, wherein the surface roughness Ra is an alumina substrate having a surface roughness Ra of 4 μm to 10 μm.

  According to the present invention, the surface layer of the semiconductor manufacturing member, that is, the surface layer, has a surface roughness Ra of 4 to 10 μm, an anchor effect is easily obtained, and the number of particles is reduced. In addition, the chemical etching process reduces microcracks and further reduces the number of particles. In other words, the particles once adhered to the surface layer exhibit an excellent anchoring effect along with the throwing action and effect, and by reducing the number of microcracks, the adhered particles and the film to be formed are separated and separated. Inconveniences and problems are avoided and eliminated.

  In addition, since the gas releasing property is also suppressed, for example, by using it as a constituent member such as a wall surface of a processing chamber for vapor deposition or sputtering, it is possible to perform processing with high yield and high reliability. Furthermore, as the microcrack that is the starting point of plasma etching is removed from the surface layer of the substrate, the plasma resistance is promoted and the influence of the microcrack is avoided, so the problem of thermal stress is also suppressed, A structural member having high mechanical durability can be provided.

In addition to having an excellent anchoring effect and heat stress resistance, it is possible to provide a semiconductor manufacturing apparatus member capable of high-reliability processing with high yield and mass production, in which gas releasing properties are also suppressed. .

  The member for a semiconductor manufacturing apparatus is manufactured by chemically etching an alumina base material. A typical surface state change of the alumina base material by chemical etching is shown in FIG. In the surface state before chemical etching in FIG. 1A, the grain boundary is selectively consumed by etching, and the surface becomes a surface roughness of, for example, Ra 1.2 μm as shown in FIG. When the etching is further continued, the deep grain boundary is etched through the etched grain boundary portion, resulting in a surface roughness of, for example, Ra 4 μm or more as shown in FIG. In addition, the member for a semiconductor manufacturing apparatus of the present invention is a member whose main component of at least the surface layer is alumina, and even if the entire member is alumina, only the surface layer or the surface layer exposed to the processing chamber of the semiconductor manufacturing apparatus is Alumina may be used.

  Thus, when the surface of an alumina base material becomes uneven | corrugated, an anchor effect arises on the surface. By chemically etching the alumina substrate, it is possible to treat the surface roughness to Ra 4 μm to Ra 10 μm, and by making this range, generation of particles can be particularly suppressed. When the surface roughness Ra is smaller than 4 μm and when the surface roughness Ra is larger than 10 μm, the generation of particles increases, and the surface roughness is preferably in the range of Ra4 μm to Ra10 μm. Although many microcracks are generated in sandblasting, the generation of microcracks can be reduced by chemical etching.

  The alumina base material is often a structural material of a vacuum apparatus, and the O-ring may maintain airtightness. Such a portion needs to be appropriately treated so as not to roughen the surface. For example, a masking treatment may be performed in advance with a mica tape coated with a silicone adhesive, and then a chemical etching treatment may be performed. It is necessary to prevent the masking part from being immersed as much as possible in the acidic solution for chemical etching.

  Embodiments will be described below with reference to the drawings.

[Comparative Example 1]
The member for a semiconductor manufacturing apparatus of Comparative Example 1 used a surface-treated alumina base material (alumina sintered body) having a purity of 99.9% by weight and an average particle size of 25 μm by a grinder treatment. Next, the alumina base material subjected to the grinder treatment was subjected to a surface processing treatment by sandblasting with SiC particles. Thereafter, the alumina substrate was cut in cross section. The image which imaged the cross section with the electron micrograph (SEM) is shown in FIG. FIG. 2A shows the surface layer of the cross section of the alumina base material, which is an enlarged image of 1000 times. FIG. 2 (B) shows the surface of the alumina base material and is an enlarged image of 2000 times. These images show that many microcracks are generated on the surface of the alumina substrate.

[Example 1]
Example 1 uses an alumina base material (sandblasted alumina base material) treated in the same manner as in Comparative Example 1, and is heated and held at 180 ° C. under a pressure of about 1 MPa (10 atm). The surface was immersed in a sulfuric acid aqueous solution of 16% by weight for 16 hours, and the surface was chemically etched. Thereafter, the alumina substrate was cut in cross section. The image which imaged the cross section with the electron micrograph is shown in FIG. FIG. 3A shows the surface layer of the cross section of the alumina base material, which is an enlarged image of 1000 times. FIG. 3B shows the surface of the alumina base material, which is an enlarged image of 2000 times. The surface has a fine concavo-convex structure from which microcracks have been removed. That is, it was confirmed that the surface had a fine concavo-convex structure and a good etching state in which microcracks were removed.

[Example 2]
Example 2 is an alumina base whose surface is chemically etched by being immersed in a 25 wt% sulfuric acid aqueous solution heated and maintained at 230 ° C. for 16 hours under a pressure of about 3 MPa (30 atm) under a grinder treatment. The material was further heat treated at 1700 ° C. for 4 hours. FIG. 4 shows an image obtained by cutting the surface after heat treatment and capturing the cross section with an electron micrograph. The surface was a fine concavo-convex structure from which microcracks were removed. FIG. 4B shows that the concavo-convex structure on the surface is clearer than that in FIG. 3B.

[Example 3]
In Example 3, the same grinder treatment and blasting treatment as in Comparative Example 1 were performed on the alumina base material by chemical etching and further heat treatment. Chemical etching and heat treatment were performed under substantially the same conditions as in Example 2. The surface was cut after heat treatment, and the cross section was taken with an electron micrograph, and the image is shown in FIG. The surface has a more uneven structure than in Example 2.

[Comparative Example 2]
In Comparative Example 2, the surface was subjected to a chemical etching treatment by immersing in a sulfuric acid aqueous solution having a concentration of 25 wt% heated and maintained at 230 ° C. for 20 hours under a pressure of about 3 MPa (30 atm) under a grinder treatment. The alumina substrate was further heat-treated at 1700 ° C. for 4 hours.

[Comparison]
Tables 1 and 3 and Comparative Examples 1 and 2 summarize the surface roughness and the number of particles.

  In all the examples, the progress of etching was smooth, and the etching state was good overall. Particularly, in Example 2, the surface roughness Ra is 7.2 and the number of particles is 33, and in Example 3, the surface roughness Ra is 10.4 and the number of particles is 35, and the number of particles is small. . In Example 1, the surface roughness Ra is 4.6 and the number of particles is 43. As a result, the surface roughness is preferably in the range of Ra4 μm to Ra10 μm. On the other hand, in the case of Comparative Example 1, the number of particles is as large as 67 and the surface layer is easily peeled off, and there are problems in plasma resistance and particle peeling / detaching properties. In the case of Comparative Example 2, the number of particles was as large as 70, and the neck of the alumina particles on the surface layer was weakened by chemical etching, so that it was easily peeled off.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention.

Schematic showing the state of the surface by chemical etching of the present invention Electron microscope image of alumina substrate surface of comparative example Electron microscope image of the alumina substrate surface of Example 1 Electron microscope image of alumina substrate surface of Example 2 Electron microscope image of alumina substrate surface of Example 3 Schematic diagram of semiconductor manufacturing equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Etching process chamber 2 ... Etching gas supply port 3 ... Discharge port 4 ... Antenna 5 ... Electromagnet 6 ... Permanent magnet 7 ... Semiconductor wafer 8 ... Lower electrode 9 ... First matching network 10 ··· First high-frequency power source 11 ··· Second matching network 12 ··· Second high-frequency power source

Claims (4)

In a semiconductor manufacturing apparatus member used in a semiconductor manufacturing apparatus for processing a semiconductor wafer,
A member for a semiconductor manufacturing apparatus, wherein the member is an alumina substrate having a surface roughness Ra of 4 μm to 10 μm.
In a semiconductor manufacturing apparatus member used in a semiconductor manufacturing apparatus for processing a semiconductor wafer,
A member for a semiconductor manufacturing apparatus, characterized by being an alumina base material having a surface roughness Ra of 4 μm to 10 μm, which is processed by chemical etching.
In a semiconductor manufacturing apparatus member used in a semiconductor manufacturing apparatus for processing a semiconductor wafer,
A member for a semiconductor manufacturing apparatus, characterized in that an alumina base material having a surface roughness Ra of 4 μm to 10 μm is subjected to a treatment by sandblasting and then a chemical etching treatment.
The member for a semiconductor manufacturing apparatus according to claim 2 or 3,
A member for a semiconductor manufacturing apparatus, wherein a heat treatment is performed after a process by chemical etching.