JP2000265160A - Abrasive for high-speed mirror surface polishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject abrasive capable of remarkably improving polishing speed, and improving productivity resulting from getting mirror surfaces in a short time by including silicon carbide minute particles with specific diameters and abrasive grain minute particles other than the silicon carbide minute particles. SOLUTION: This abrasive material is obtained by including (A) silicon carbide minute particles each having a diameter of <=0.1 μm and (B) abrasive grain minute particles other than the component A. It is desirable that the proportion of the component A to be compounded is 0.1 to 60 wt.% based on the total amount of the components A and B. The component A is produced, for example, by introducing a raw material gas composed of a silane compound or silicon halide and a hydrocarbon, in a plasma of nonoxidative atomosphere and conducting a vapor phase reaction while controlling the pressure of the reaction system so as to be in the range of >1 atm. to 0.1 Torr. The component B is desirably selected from SiO2, Al2O3, ZrO2, CeO2, Fe2O3, Fe3O4, Cr2O3, MnO2, BaCO3, and CaCO3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to polishing of semiconductor wafers such as silicon wafers, optical crystals such as quartz, quartz, and sapphire, glass substrates such as optical lenses, magnetic disks, various metal materials, and various ceramic materials. The present invention relates to an abrasive for high-speed mirror polishing capable of mirror-polishing a workpiece at a high speed.

[0002]

2. Description of the Related Art Conventionally, for mirror polishing of a silicon wafer, a GaAs wafer, or the like, for example, colloidal silica or Ce
Polishing slurries and polishing whetstones using O ₂ fine particles have been used.

[Problems] However, when these polishing materials are used for polishing, the polishing rate is extremely low, a long time is required to obtain a mirror surface, and the productivity is low. In addition, since the polishing rate is low, lapping or grinding must be performed as a pre-processing for mirror polishing, and mirror polishing must be performed after removing the processing damage layer by etching, resulting in extremely low productivity. It was a process.

On the other hand, as an abrasive having a high polishing rate, an abrasive containing silicon carbide particles having a particle diameter of sub-μm or more and alumina particles or silica particles is known, and a polishing agent containing such abrasive grains is known. When the workpiece is polished using a material, a relatively high polishing rate can be achieved, but a mirror surface cannot be obtained, and the surface roughness (Ra) of the obtained polished body is at most about several tens to several hundreds of nm. Was. In addition, "surface roughness (R
"a)" refers to the average of the steps (center line average roughness) of the steps between the projections and the depressions on the surface of the polishing body, as measured by a contact pointer type surface roughness meter or the like.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and the problems specifically set for that purpose are that the polishing rate is significantly improved, An object of the present invention is to provide an abrasive for high-speed mirror polishing in which a mirror surface is obtained by the above method and productivity is improved.

[0006]

Means for Solving the Problems The above-mentioned object is attained with a particle size of 0.1 μm.
The problem can be solved by an abrasive containing at least m silicon carbide fine particles and abrasive fine particles other than the silicon carbide fine particles. Here, the mixing ratio of the silicon carbide fine particles is preferably 0.1 to 60% by weight based on the total amount of the silicon carbide fine particles and the abrasive fine particles other than the silicon carbide fine particles. The abrasive particles other than the silicon carbide particles include SiO ₂ , Al ₂ O ₃ , ZrO ₂ , Ce
O ₂ , Fe ₂ O ₃ , Fe ₃ O ₄ , Cr ₂ O ₃ , Mn
It is preferably at least one selected from the group consisting of O ₂ , BaCO ₃ , and CaCO ₃ .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. However, this embodiment is specifically described for better understanding of the gist of the invention, and does not limit the content of the invention unless otherwise specified.

The abrasive according to the present embodiment contains, as abrasive grains, at least silicon carbide fine particles having a particle size of 0.1 μm or less and abrasive fine particles other than the silicon carbide fine particles. The silicon carbide fine particles may be produced by any method, for example, by introducing a raw material gas comprising a silane compound or silicon halide and a hydrocarbon into plasma in a non-oxidizing atmosphere, The pressure of the reaction system from less than 1 atmosphere
The one manufactured by performing a gas phase reaction while controlling within a range of 0.1 torr (hereinafter referred to as “silicon carbide fine particles obtained by plasma vapor synthesis”) is likely to have the polishing mechanism described below, and has a spherical shape. It is suitable in that it is fine and fine and has high purity.

Although the polishing mechanism of the workpiece to be polished by the present abrasive is not always clear, silicon carbide fine particles having a particle diameter of 0.1 μm or less have a very active surface, and the silicon carbide fine particles have a true contact point with the workpiece. A solid phase reaction between the two or an oxidation reaction on the surface of the workpiece to be polished occurs, and the resulting layer is removed by fine particles of silicon carbide and fine particles other than the fine particles of silicon carbide, so that a high mirror polishing rate can be obtained. Conceivable. That is, it is considered that the addition of the fine-grain silicon carbide abrasive grains achieves high-speed mirror polishing by adding a polishing promoting effect to the conventional polishing using the mirror polishing abrasive grains.

[0010] In the above-mentioned abrasive, the compounding ratio of the silicon carbide fine particles is preferably 0.1 to 60% by weight based on the total amount of the silicon carbide fine particles and the abrasive fine particles other than the silicon carbide fine particles. When the ratio of the silicon carbide fine particles to the total amount of the abrasive grains is less than 0.1% by weight, the high-speed mirror polishing as the object of the present invention cannot be achieved,
If the ratio exceeds 60% by weight, the mirror polishing speed is not improved, so that it is disadvantageous in cost.

The abrasive particles other than the silicon carbide particles are:
SiO_Two, Al_TwoO_Three, ZrO_Two, CeO_Two, Fe_TwoO
_Three, Fe_ThreeO_Four, Cr_TwoO_Three, MnO_Two, BaCO_Three,
CaCO_ThreeAt least one selected from the group consisting of
SiO_Two, CeO_Two, Fe _TwoO_Three, Cr_TwoO_Three, Mn
O_Two, BaCO_Three, CaCO_ThreeSelected from the group consisting of
Mechanochemical mirror polishing to be at least one kind
This is preferable in that is promoted. In addition, the silicon carbide fine particles
The particle size of the abrasive particles other than the particles is not particularly limited.
No, for example, the degree that is usually used as an abrasive
So good.

An example of a typical polishing method using the above-mentioned polishing material is as follows. A slurry or paste in which the above-mentioned polishing material is added and dispersed is supplied between a polishing cloth and a work to be polished and rotated to obtain a wet mirror surface. There is a method of performing polishing, a method of forming the polishing material into a grindstone or tape shape, or a method of performing mirror polishing by bringing a polishing body fixed in a foam into contact with a workpiece to be polished.

In order to form the grinding stone, there are cases where the whole grinding stone is formed by the above-mentioned abrasive material and where the contact portion of the grinding stone with the workpiece to be polished is partially formed. Can be solidified without a binder (bondless grindstone), or solidified using a binder such as resinoid bond or the like (resinoid bond grindstone).
The abrasive grain ratio (volume ratio of the abrasive grains in the grindstone) of the grindstone is not particularly limited, and may be generally about 5 to 95% by volume.

The resinoid bond used for forming the resinoid bond grindstone may be a known thermosetting resin, thermoplastic resin,
A simple substance such as a water-soluble polymer resin or a mixture thereof can be used. In addition, the resinoid bond grindstone or the bondless grindstone can be formed by using a generally used known molding technique.

On the other hand, in order to obtain a slurry (polishing liquid) in which the abrasive is added and dispersed, it is preferable that silicon carbide fine particles having a particle size of 0.1 μm or less are crushed to near primary particles and dispersed. . In that case, a polycarboxylic acid-based surfactant or the like may be used in combination.

The amount of abrasive grains in the polishing liquid is not particularly limited, but a preferred amount of abrasive grains is 1 to
It is about 15% by weight. If the amount of the abrasive particles is too small, the polishing rate will be too low, resulting in lack of practicality, and if the amount of the abrasive particles is too large, the number of abrasive particles not contributing to the polishing will increase, and the polishing liquid cost will increase, resulting in an increase in the polishing cost. Undesirably increases.

In the case of the polishing method exemplified above, a solution containing an acid or an alkali component is dropped between the polishing body and the workpiece to be polished, depending on the type of the workpiece. Polishing is effective.

According to such an embodiment, a particle size of 0.1
μm or less silicon carbide fine particles, in order to use an abrasive composed of abrasive particles other than the silicon carbide fine particles as an abrasive,
High-speed mirror polishing can be performed without causing processing damage to the surface of the workpiece during mirror polishing.

Therefore, by performing these polishing methods, the performance of the conventional mirror-polished material, particularly the mirror-polishing speed, can be greatly improved. Ra) is, for example, 1 nm
Mirror polishing to the extent possible.
In addition to semiconductor wafers such as aAs, quartz, LiNbO ₃ ,
Optical substrates such as sapphire, liquid crystal, optical lenses, cathode ray tubes, glass substrates such as photomasks, magnetic disks,
Mirror-polished workpieces to be polished, such as various metal materials and various ceramic materials, can be made compatible with high productivity and low cost.

[0020]

EXAMPLES Example 1 Silicon carbide fine particles (Sumitomo Osaka Cement Co., Ltd.) obtained by a plasma gas phase synthesis method were used in 100 ml of a slurry for primary polishing of silicon wafers containing colloidal silica (manufactured by Fujimi Incorporated). )
Made with water 1900
The resulting dispersion was added and mixed to obtain a polishing slurry (total abrasive content: 5% by weight, silicon carbide fine particles: 10% by weight based on the total amount of abrasives). Using this polishing slurry, a wrapped Si wafer was polished under the polishing conditions shown in Table 1 (polishing time 30
Minutes). Table 3 shows the results. The surface roughness (R
a) was measured by a contact pointer type surface roughness meter.

Example 2 A wrapped Si wafer was polished in the same manner as in Example 1 except that the ratio of the silicon carbide fine particles obtained by the plasma vapor synthesis method to the total abrasive content was 20% by weight. Table 3 shows the results.

Example 3 Silicon carbide fine particles obtained by plasma gas phase synthesis in 100 ml of an aqueous dispersion in which 10% by weight of cerium oxide fine particles (manufactured by Shin-Etsu Chemical Co., Ltd., average particle size: 100 nm) were dispersed. (Sumitomo Osaka Cement Co., Ltd., particle size
A dispersion in which 1900 ml of water in which 0.05 μm or less and an average particle size of 30 nm are dispersed is added and mixed, and the mixture is dispersed using ultrasonic waves. The slurry for polishing (total abrasive content: 5% by weight, total abrasive amount) 20% by weight of silicon carbide fine particles based on Using this polishing slurry, the optical glass BK-7 was polished under the polishing conditions shown in Table 1. Table 3 shows the results.

Example 4 855 g of silica powder (manufactured by Nippon Aerosil Co., Ltd., average particle size: 30 nm) and silicon carbide fine particles obtained by plasma vapor synthesis (manufactured by Sumitomo Osaka Cement Co., Ltd., particle size: 0.05 μm or less, average particle size 30 nm) 9
5 g, phenolic resin (Sumitomo Durez Co., Ltd.) 50 g
Was mixed to form a grindstone (amount of silicon carbide particles was 10% by weight based on the total amount of abrasive grains). Using this grindstone, polishing of the wrapped Si wafer was performed for 30 minutes under the polishing conditions shown in Table 2,
Table 3 shows the results.

Example 5 A lapped Si wafer was polished in the same manner as in Example 4 except that the ratio of the silicon carbide fine particles obtained by the plasma vapor synthesis method to the total abrasive content was 30% by weight. Table 3 shows the results.

Example 6 Silica powder was converted to cerium oxide fine particles (Shin-Etsu Chemical Co., Ltd., average particle size 100 nm).
A whetstone was formed in the same manner as in Example 4 except for changing to. Using this grindstone, the optical glass BK-7 was polished according to Example 4, and the results are shown in Table 3.

Comparative Example 1 A wrapped Si wafer was polished in the same manner as in Example 1, except that a slurry for primary polishing of a silicon wafer containing colloidal silica (manufactured by Fujimi Incorporated) was used. Table 3 shows the results.
It was shown to.

Comparative Example 2 875 g of silica powder (manufactured by Nippon Aerosil Co., Ltd., average particle size: 30 nm) and 50 g of phenol resin (manufactured by Sumitomo Dellurez Co., Ltd.) were mixed to form a grindstone. In accordance with Example 1, the wrapped Si wafer was polished. Table 3 shows the results.

Comparative Example 3 A wrapped Si wafer was polished in the same manner as in Example 1 except that silicon carbide fine particles having a particle size of 0.3 μm (manufactured by Ibiden Co., Ltd.) were used. Table 3 shows the results.

Comparative Example 4 A grindstone was formed in the same manner as in Example 4 except that silicon carbide fine particles having a particle diameter of 0.3 μm (manufactured by IBIDEN Co., Ltd.) were used. A wrapped Si wafer was polished according to Example 4. Table 3 shows the results.

Comparative Example 5 50 g of cerium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 100 nm) was added to 950 g of water.
The mixture was mixed and dispersed using ultrasonic waves to obtain a polishing slurry (abrasive content: 5% by weight). Using this polishing slurry, the optical glass BK-7 was polished under the polishing conditions shown in Table 1. Table 3 shows the results.

Comparative Example 6 950 g of cerium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 100 nm) and 50 g of phenol resin (manufactured by Sumitomo Durez Co., Ltd.) were mixed to form a grindstone. Using this grindstone, polishing of the optical glass BK-7 was performed for 30 minutes under the polishing conditions shown in Table 2, and the results are shown in Table 3.

[Comparative Example 7] Silicon carbide fine particles obtained by a plasma gas phase synthesis method (manufactured by Sumitomo Osaka Cement Co., Ltd., particle size
0.05 μm or less, average particle size 30 nm) 50 g to water 950 g
Was added to and mixed with the mixture, and dispersed using ultrasonic waves to obtain a polishing slurry (abrasive content: 5% by weight). Using this polishing slurry, a wrapped Si wafer was polished under the polishing conditions shown in Table 1. Table 3 shows the results.

[Comparative Example 8] Silicon carbide fine particles obtained by a plasma gas phase synthesis method (manufactured by Sumitomo Osaka Cement Co., Ltd., particle size
950 g of 0.05 μm or less, average particle size of 30 nm) and 50 g of phenol resin (manufactured by Sumitomo Durez Co., Ltd.) were mixed to form a grindstone. Using this grindstone, polishing of the wrapped Si wafer was performed for 30 minutes under the polishing conditions shown in Table 2, and the results are shown in Table 3.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

According to the present invention as described above, claim 1
In the abrasive for high-speed mirror polishing according to the present invention, the abrasive is configured to contain at least silicon carbide fine particles having a particle diameter of 0.1 μm or less and abrasive fine particles other than the silicon carbide fine particles, the conventional mirror-polished abrasive Since the performance, especially the mirror polishing speed, can be greatly improved, the mirror polishing with a surface roughness (Ra) of, for example, about 1.0 nm can be performed immediately after the lapping or grinding, and the silicon wafer or GaAs can be formed.
In addition to semiconductor wafers such as s, optical crystals such as quartz, LiNbO ₃ , sapphire, glass substrates such as liquid crystals, optical lenses, cathode ray tubes and photomasks, magnetic disks, various metal materials, and various polished workpieces such as various ceramic materials Can be mirror-polished while achieving both high productivity and low cost.

In the abrasive for high-speed mirror polishing according to claim 2, the mixing ratio of the silicon carbide fine particles is 0.1% with respect to the total amount of the silicon carbide fine particles and the abrasive fine particles other than the silicon carbide fine particles. When the content is up to 60% by weight, mirror polishing can be efficiently performed at high speed, and productivity is improved.

The polishing for high-speed mirror polishing according to the third aspect.
In the material, abrasive particles other than the silicon carbide particles are Si
O_Two, Al_TwoO_Three, ZrO_Two, CeO_Two, Fe_TwoO_Three,
Fe _ThreeO_Four, Cr_TwoO_Three, MnO_Two, BaCO_Three, Ca
CO_ThreeAt least one member selected from the group consisting of
High-speed mirror polishing by mechanochemical mirror polishing
Can be.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H01L 21/304 622 H01L 21/304 622B (72) Inventor Yoshiki Yamamoto 585 Tomicho, Funabashi-shi, Chiba Prefecture Sumitomo Osaka F-term in Cement Corporation New Technology Research Laboratory (reference) 3C063 AA01 AB01 BB01 BB04 BB07 BB19 BC02 BC03 EE10 FF23

Claims (3)

[Claims] An abrasive for high-speed mirror polishing, comprising at least silicon carbide fine particles having a particle size of 0.1 μm or less and abrasive fine particles other than the silicon carbide fine particles. 2. The high-speed mirror surface according to claim 1, wherein the mixing ratio of said silicon carbide fine particles is 0.1 to 60% by weight based on the total amount of said silicon carbide fine particles and said abrasive fine particles other than said silicon carbide fine particles. Abrasive for polishing. 3. The abrasive fine particles other than the silicon carbide fine particles,
SiO ₂ , Al ₂ O ₃ , ZrO ₂ , CeO ₂ , Fe ₂ O
₃ , Fe ₃ O ₄ , Cr ₂ O ₃ , MnO ₂ , BaCO ₃ ,
_{3. The} abrasive for high-speed mirror polishing according to claim 1, wherein the abrasive is at least one member selected from the group consisting of CaCO ₃ .