JPH0424187B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to an abrasive material useful for polishing the surfaces of semiconductors, optical equipment, etc., and particularly to a fine powder abrasive material that quickly imparts an excellent polished surface to these materials to be polished. It is related to materials. (Prior art and its problems) Conventionally, about 50-50% by weight of brown fused alumina and zircon (ZrSiO ₄ ) was used for surface polishing in the above-mentioned fields.
A fine abrasive consisting of a mixture is used. This abrasive has a maximum particle size of 16 μm or less, and a particle size of 4
Particles in the range of ~16 μm account for 99 to 100% by weight of the total, and particles of 4 μm or less are hardly included.
When this fine powder abrasive is used to polish the surface of the above-mentioned material to be polished, many scratches occur on the surface, which significantly reduces the yield of the product and makes it impossible to increase the polishing speed. Therefore, in order to increase productivity and abrasive grain consumption, attempts were made to increase the polishing speed by using abrasive grains with a larger grain size, but it was found that the machining accuracy of the polished surface decreased in proportion to the speed. Due to problems, it was not put into practical use. For this reason, there has been a strong desire for the emergence of a fine powder abrasive that can quickly provide an excellent machined surface without scratches. (Means for Solving the Problems) The present invention was achieved based on the above circumstances, and an object of the present invention is to provide a fine powder abrasive that can provide an excellent machined surface even at a high polishing speed. That is, as a result of various studies, the present inventors have found that this fine powder abrasive is made of a mixture of 10 to 90% by weight of brown fused alumina and 90 to 10% by weight of zircon, and has a maximum particle size of 16 μm or less and an average particle size of 6 to 6 μm. It is a fine powder of 7 μm, and particles with a particle size of 4 μm or more and 16 μm or less account for 85 to 95% by weight of the total (preferably a particle size of 10.1 μm).
2 to 7% of the total weight of particles from m to 16μm, 40 to 60% by weight of particles from 6.35μm to 10.1μm, and 30 to 40% of particles from 4.00μm to 6.35μm.
(wt%) and 15 to 5 wt% particles less than 4 μm.
If it has a particle size distribution of If the amount of particles is less than 5% by weight, there is no effect;
The present invention was completed based on the discovery that scratches occur more frequently when the content exceeds 10% by weight. (Examples) Hereinafter, the details of the present invention will be explained based on Examples, but the present invention is not limited thereto. Example 1 50% by weight brown fused alumina and 50% by weight zircon
A fine powder abrasive material having a particle size distribution shown in Table 1 (particle size was measured by the electrical resistance method) was produced as a prototype. In order to evaluate this prototype, we compared it with a commercially available product (its particle size distribution is also listed in Table 1).
Each was prepared as a slurry suspended in water, and using a silicon wafer as the workpiece, the number of rotations of the surface plate was adjusted using a wrapping machine (manufactured by Fujikoshi Machine Industry Co., Ltd.).
Polishing was carried out under the conditions of 63 rpm and a load of 100 g/cm ² by supplying the polishing material in a continuous manner. The results are shown in Table 2.

【table】

[Table] As is clear from the table, when silicon wafers were polished using the abrasive of the present invention (especially 4 μm
In the case of prototypes A and B, which have a particle size distribution of 15 to 5% by weight), the occurrence of scratches on the polished surface is extremely small compared to when commercial products are used, and the polished surface is excellent. is obtained, and
It was found that the polishing speed was high even though the average grain size of the prototype was smaller. Example 2 The mixing ratio of brown fused alumina and zircon is 15:
85, 45:55, and 75:25, and have the particle size distributions shown in Table 3. We produced three types of abrasives as prototypes, performed abrasive processing in the same manner as in the previous example, measured their abrasive characteristics, and determined the characteristics of the prototypes. I conducted an evaluation. The results are shown in Table 4.

【table】

【table】

[Table] As is clear from the table, no scratches occur and the surface roughness is excellent even when the mixing ratio of brown fused alumina and zircon in the fine powder abrasive is changed. (Effect of the invention) As described above, the fine powder abrasive of the present invention has Si,
It is extremely useful as an abrasive for semiconductors such as GaP and GaAs, and optical glass materials.

Claims (1)

[Claims] 1 Brown fused alumina 10-90% by weight and zircon 90
~10% by weight mixture with maximum particle size of 16μ
m or less, a fine powder with an average particle diameter of 6 to 7 μm,
Particles with a particle size of 4μm or more and 16μm or less account for 85 to 100% of the total particles.
1. A fine powder abrasive material having a particle size distribution of 95% by weight and 15% to 5% by weight of particles less than 4 μm.