JP2000127030A - Carrier material and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a strong, thin and large carrier material having little metal pollution and used for a polishing machine for applying mirror finish to the surface of a plate-like work required with extremely high flatness and parallelism such as a silicone wafer. SOLUTION: A resin such as a thermosetting resin or a thermoplastic resin is reinforced by a layered product laminated with fabrics made of at least one of raw materials selected from sheets such as a metal sheet or a ceramic sheet, metal fibers, ceramic fibers, glass fibers, carbon fibers or organic synthetic fibers to form a thin plate of a composite material for a carrier material. The thermosetting resin or the thermoplastic resin contains colloidal metal oxide fine grains and/or inorganic fine powder. The carrier material may contain at least one of colloidal metal oxide, nitride, carbide or other inorganic fine grains in the said organic synthetic fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a planetary motion by holding a workpiece as a workpiece when polishing a silicon wafer, a magnetic disk substrate, a crystal oscillator, or the like using a double-side polishing machine. More particularly, the present invention relates to a carrier material comprising a fiber-reinforced plastic sheet in which a cloth made of glass fiber or organic fiber and an epoxy resin, a phenol resin or a melamine resin are combined, and a method for producing the same. .

In polishing a workpiece made of a silicon wafer, a compound semiconductor wafer, a magnetic disk substrate made of aluminum, a magnetic disk substrate made of glass or a glass for a fort mask, a crystal oscillator, a metal, or the like, the workpiece is formed by polishing the workpiece. It has a holding hole according to the shape and is held by a carrier material cut and molded so as to have outer teeth meshing with the internal gear of the double-side polishing machine and the gear of the sun wheel on the outer peripheral edge thereof, Driven. This carrier material is mainly used as a member of a polishing apparatus for simultaneously performing lapping and polishing of both surfaces of a wafer or a disk. Therefore, it is necessary that the thickness of the carrier material is made slightly smaller than the thickness of a workpiece such as a wafer.

[0003]

2. Description of the Related Art Conventionally, these carrier materials are made by impregnating a glass cloth or an organic fiber cloth woven of glass fibers with an epoxy resin, a phenol resin, or other thermosetting resin, and compressing them by a stacking press to a desired thickness. Using a flat substrate made by heating and curing as a material, cut it into a size that can hold the workpiece according to the purpose of use,
Further, it is generally manufactured by a method of cutting the outer periphery according to the gear shape.

[0004] These carrier materials are polished together with workpieces such as wafers and discs in a polishing apparatus, and are forcibly driven by internal gears and sun wheels through outer peripheral teeth, so that their strength is reduced. Drop,
The durability deteriorates with time due to the deterioration of the shape accuracy, and the gear part is worn out, comes out of the polishing device, and the polishing conditions become unstable. Will be replaced. Therefore, development of a durable carrier material that can be used for a little longer time has been strongly desired. On the other hand, for lapping semiconductor wafers, metal special steel-based carrier materials that are thin and can withstand high stress double-side polishing have been mainly used.
However, as silicon wafers become more highly purified in the future, contamination of iron from special steel, which has not been a problem in the past, has become a problem, and it has become clear that it is undesirable.

In recent years, the demand for increasing the size of these silicon wafers and the productivity of magnetic disk substrates has led to an increase in the size of the apparatus. This has led to an increase in the strength of the carrier material, an increase in the flexural modulus, and a reduction in bending. Therefore, there is a strong demand for improving the physical properties of the carrier material.
In addition, the demand for high purity is becoming stricter when silicon wafers and magnetic disk substrates are used, and glass fiber cloths, which have been widely used in the past, generate scratches due to the generation of dust mainly in the gears due to the scratching of magnetic disk polishing. This is a cause, and in particular, the content of sodium ions and boron which are disliked by semiconductors in silicon wafers is beginning to be regarded as a problem. Furthermore, during the polishing process, heat fluctuates greatly, and there are many opportunities to be exposed to acids, alkalis, organic solvents, and the like. Therefore, in addition to mechanical properties, dimensional stability and chemical stability are required. .

[0006]

In view of the problems that have recently been raised with respect to the above-mentioned carrier materials, the present inventors have made various studies and found that the composite fiber material and the resin contained colloidal metal in the resin. Oxide, nitride, carbide or other fine particles or other inorganic fine particles to be added internally,
Further, the present inventors have found that by using a porous metal sheet or a ceramic sheet as a composite material sheet, the strength and physical properties of the carrier material as a whole can be improved, and have completed the present invention. The purpose is to provide a carrier material which is thin, tough and excellent in dimensional stability, and a further object is to provide a method for producing the same.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a carrier material used for holding a workpiece in a double-side polishing apparatus, wherein the carrier material is made of a thermosetting resin or a thermoplastic resin. Reinforced by a sheet made of a sheet made of a ceramic sheet, a sheet made of a ceramic sheet, or a laminate of a cloth made of at least one material selected from metal fibers, ceramic fibers, glass fibers, carbon fibers and organic synthetic fibers. And a carrier material characterized in that the thermosetting resin or the thermoplastic resin contains colloidal metal oxide fine particles and / or inorganic fine powder internally. be able to. Further, the carrier material is a resin made of a thermosetting resin or a thermoplastic resin, and an organic synthetic fiber in which at least one of colloidal metal oxides, nitrides, carbides, and other inorganic fine particles is internally added. It may be made of a thin plate of a composite material reinforced with a laminate obtained by laminating a cloth as a material. In the above-mentioned carrier material, it is preferable that the metal sheet and the ceramic sheet are porous having through holes.

[0008] The thermosetting resin referred to in the present invention is a synthetic resin which is thermally cured by heating to be in an insoluble and infusible state, and is a urea resin, an epoxy resin, a phenol resin, a melamine resin, a polyimide resin, an unsaturated polyester resin. Alkyd resin, urethane resin and the like, and in the present invention, epoxy resin, phenol resin, melamine resin and polyimide resin are particularly preferable. In addition, a thermoplastic resin is a resin that does not cause a structural change even when heated, and a polyamide resin or a polyester resin can be used in the present invention.

In the present invention, the colloidal metal oxide which can be mixed with a thermosetting resin or a thermoplastic resin includes cerium oxide, alumina, zirconia, ceria having a particle size of 1 μm or less and an average particle size of 1 nm or more. , Refers to titania. These fine particles are formed, for example, by hydrolyzing sodium silicate, aluminum nitrate, zirconium oxychloride, tetramethoxysilicon, and many other inorganic salts, organic metal salts and metal acid salts in water or a water-soluble organic solvent to form colloidal particles. The particles can be obtained by a method of producing fine particles, a method of forming fine powder of silica, alumina, zirconia or the like produced at a high temperature into a colloid in water using a colloid mill or a homogenizer.

In the present invention, the inorganic powder which can be mixed with the thermosetting resin or the thermoplastic resin is added to improve the elastic modulus of the resin, and the powder particles have a particle diameter of submicron to 50 micron. Silica, alumina, zirconia, titania, silicon nitride, boron nitride,
Examples include aluminum nitride, silicon carbide, boron carbide, and diamond.

In the present invention, the fine particles of colloidal metal oxides, nitrides, and carbides that can be mixed with organic synthetic fibers are cerium oxide and alumina having a particle size of 1 μm or less and an average particle size of 1 nm or more. , Zirconia, ceria, titania, silicon nitride, boron nitride, aluminum nitride, silicon carbide, boron carbide, and the like. These fine particles are, for example, sodium silicate, aluminum nitrate, zirconium oxychloride, tetramethoxysilicon and many other inorganic salts,
Methods of hydrolyzing organometallic salts and metal salts in water or water-soluble organic solvents to produce colloid-sized particles, and those produced at high temperatures such as silica, alumina, zirconia, aluminum nitride, and silicon carbide. It can be obtained by a method in which fine powder is converted into colloid in water using a colloid mill or a homogenizer.

In the present invention, the inorganic fine particles which can be mixed with the organic synthetic fibers refer to fillers for reinforcing the strength of the synthetic fibers, and examples thereof include fine powders of boron nitride and silicon carbide fibers.

The metal sheet used in the present invention is:
It is preferably a sheet made of iron, stainless steel, copper, titanium, aluminum, or the like, and preferably has a large number of minute through holes on its surface. The reason for providing the minute through-holes is to avoid the occurrence of phenomena such as separation of the resin and metal on the sheet surface due to the communication of the composite resin through the holes. Therefore, any method can be used to form the holes with good bonding properties with the composite resin. For example, it is preferable that there are fine mesh-like holes or 10 to 50% of checkerboard holes in combination with the resin.

Examples of the inorganic sheet include a ceramic sheet made of alumina, zirconia, mullite, cordierite, or the like, or silica fiber, potassium titanate fiber, glass fiber, stainless fiber, or the like.
Short-fiber or long-fiber materials such as titanium fibers can be used as low-melting glass, solder, or nonwoven fabrics formed by fusing themselves. It is preferable that the surface has a large number of minute through holes. The method of forming the holes is the same as that of the above-described metal sheet, and any method having good bonding properties with the composite resin can be used. For example, a fine mesh-like hole or a hole in a checkerboard pattern with about 10 to 50% of the surface area is preferable for a composite with a resin.

In the case where the carrier material according to the present invention is used for processing a silicon wafer in which the content of sodium ions or boron which is disliked by semiconductors is considered to be a problem, a material other than glass fiber is selectively used. A carrier material can be used.

Next, a method of manufacturing a carrier material which is another object of the present invention will be described in detail. The carrier material of the present invention,
Insufficient mechanical strength, rigidity or dimensional stability of resin is compensated for by combining it with other material sheets. It is important to do this. In particular,
The present invention is characterized in that a colloidal or particulate additive is added to the resin.

In the production, first, a colloidal or particulate additive is uniformly dispersed in a liquid of a prepolymer or a precursor when the resin to be used is a thermosetting resin, and then the liquid is used. A so-called prepreg is prepared by impregnating a reinforcing sheet to be laminated, and a plurality of such prepregs are laminated as needed, and then pressurized and heated to perform thermosetting to obtain an original carrier material sheet. The desired carrier material can be obtained by punching and molding this into the desired shape. When curing, curing with a curing agent or curing with light or ultraviolet light may be used in combination. If the resin to be used is a thermoplastic resin, use a homogenous dispersion of colloidal or fine particles of the additive in the solvent of the resin, or homogenously disperse the additive while the resin itself is melted. Impregnating a reinforcing sheet to be laminated, and stacking a plurality of the sheets,
Press molding is performed by pressurizing and heating to obtain an original plate of the carrier material. The desired carrier material can be obtained by punching and molding this into the desired shape.

When producing at least one of colloidal metal oxides, nitrides, carbides and other inorganic fine particles in an organic synthetic fiber, a raw material of the organic synthetic fiber is used. The polymer is spun in a state in which necessary additives are kneaded into the polymer to produce fibers, which are woven or knitted into a fabric.

The polishing apparatus according to the present invention includes a semiconductor silicon wafer, an aluminum or glass magnetic disk substrate, a crystal,
It is used in a lapping process and a polishing process for a photomask glass or the like, and is mainly used for a double-side polishing machine using this carrier material. However, the present invention can also be applied to a single-side polishing machine using a carrier material.

[0020]

EXAMPLES and COMPARATIVE EXAMPLES The method of the present invention will be specifically described below with reference to examples, but the present invention is not particularly limited thereby.

Example 1 A colloidal zirconia dispersion composed of spherical zirconia particles having an average particle diameter of 110 nm was added to a melamine resin liquid having a solid content of 80% by weight at a zirconia solid content concentration of 5% by weight based on the resin solid content. %, And this was impregnated into a glass fiber cloth. This cloth is laminated in three layers and cured under pressure under normal conditions, and the sheet thickness is 0.6 mm.
Was obtained. The blank was punched out according to the specifications of a carrier plate of a double-side polishing machine 5B-8LP manufactured by Speed Fam Co., Ltd. to prepare a carrier plate, and the carrier plate was loaded into the polishing machine. In the case of this double-side polishing machine, 8
One carrier plate can be loaded, and each carrier plate can be loaded with one 2.5-inch workpiece. In the experiment, the workpiece was not loaded,
Surface pressure 200 g / cm with silica slurry containing 8% solids
^{2. The} number of rotations of the carrier is 30 rpm (sun gear 36r
pm, internal gear 16 rpm), continue the processing and polishing test at a slurry supply rate of 400 cc / min for 20 hours, measure the wear amount of the involute type gear of the carrier and the carrier thickness reduction amount after 20 hours, and calculate the average value. I asked. The measurement of the amount of wear of the gear
The measurement was performed at a position of 5 mm. This test was repeated three times.

Comparative Example 1 As a comparative example, a carrier was prepared under the same conditions as in Example 1 of the present invention except that colloidal zirconia was not contained in the melamine resin solution, and a working polishing test was carried out. This test was also repeated three times. Table 1 shows the results obtained in Example 1 and Comparative Example 1. As is evident from the results shown in Table 1, the carrier using the melamine resin containing colloidal zirconia according to the method of the present invention showed significantly less reduction in wear due to gear contact and reduction in plate thickness due to polishing.

[0023]

[Table 1]

Example 2 and Comparative Example 2 As shown in Example 1, a SUS metal thin film sheet having a thickness of 0.5 mm and circular holes having a diameter of 2 mm and containing about 40% of the sheet area contains colloidal zirconia. The sheet was impregnated with a phenol resin solution, the sheets were laminated in five layers, and a thermosetting square carrier base plate having a size of 100 mm was prepared.
Further, a carrier base plate was similarly prepared using a 0.5 mm alumina ceramic sheet. Separately from this, as a comparative example, a sheet made of aramid fiber cloth having a thickness of 0.5 mm was impregnated with a phenol resin liquid containing no additive, and the sheets were laminated in five layers and thermoset. 10
A 0 mm square carrier base plate was prepared. The obtained carrier base plate was stored in a dry state at a humidity of 40% for one week to prepare a sample piece. Another sample piece was stored in water for 24 hours, taken out of the water and air-dried at room temperature for 3 hours. The dimensional difference from the treated one was measured and defined as dimensional stability. Table 2 summarizes the results. As is clear from the results in Table 2, the carrier plate according to the present invention exhibits excellent dimensional stability.

[0025]

[Table 2]

Example 3 and Comparative Example 3 A dispersion of colloidal alumina, fine powder of boron nitride fiber, and fine powder of silicon carbide were kneaded at 3% solid content to a raw material polymer of polyester fiber, and the mixture was spun to produce polyester fiber. This was woven to obtain a rigid polyester sheet. This sheet was impregnated with an epoxy resin liquid, and five layers were laminated and hot-pressed to obtain a carrier plate. This is referred to as a third embodiment. As Comparative Example 3, a carrier base plate was obtained in the same manner as described above, except that colloidal alumina, boron nitride fiber fine powder, and polyester fiber not containing silicon carbide fine powder were used. The abrasion resistance and the elastic modulus of these carrier plates were evaluated by the following methods. Prepared carrier plate 2
The test piece was punched out to a size of 0 × 20 mm to measure the amount of wear. This test piece was rotated at a load of 200 g / cm ² and a rotation speed of 80 rpm using a doctor lap polishing tester manufactured by Maruto Co., Ltd., and 500 ml / min of a 2% solids silica slurry was supplied thereto. For a minute, the difference in thickness before and after the polishing was taken as the amount of wear. Also,
A rectangular test piece with a size of 120 × 10 mm was prepared, and in order to measure the warpage prevention effect due to the load of the carrier base plate, a long dimension of 100 mm was supported at two points, and a thread was placed 50 mm from both sides in the middle. The weight set from the horizontal plane after 10 minutes was added by adding a load of 40 g suspended from the above. The smaller the size, the smaller the warpage and the higher the elastic modulus.

Table 3 shows the results obtained by these evaluation tests. As is clear from the results in Table 3, it is confirmed that the carrier base plate of the method of the present invention is clearly excellent in abrasion resistance, has high rigidity, and is suitable for a large carrier plate.

[0028]

[Table 3]

[0029]

The carrier material according to the present invention is superior in strength, rigidity and abrasion resistance as compared with the conventional carrier material, so that the size of the polishing machine can be increased and the thickness of the workpiece can be reduced. It is possible to provide a carrier that is strong in a direction and can be used for a long time. In addition, it has good stability to temperature and water, and does not suffer from damage due to deformation or deterioration and does not impair productivity. In addition, by appropriately selecting the type of reinforcing fibers and sheets, the type of colloidal metal oxide to be compounded, and the type of fine powder particles, a carrier using a material that does not cause metal contamination or other impurities. Therefore, for example, in order to prevent contamination by an alkali metal such as sodium, a material other than glass fiber may be used.

Continued on the front page (72) Inventor Yoshihisa Ogawa 2647 Hayakawa, Hayakawa, Ayase City, Kanagawa Prefecture (72) Inventor Yusuke Inoue 2647, Hayakawa, Ayase City, Kanagawa Prefecture Speed Fam Corporation (72) Inventor Seichiro Futami Ayase, Kanagawa Prefecture 2647 Hayakawa-shi Speed Fam Co., Ltd. (72) Inventor Michihiko Hosaka 2647 Hayakawa Hayakawa, Ayase-shi, Kanagawa F-term Co., Ltd. F-term (reference) 3C058 AA07 AB04 DA06 DA09 DA17

Claims (5)

[Claims] 1. A carrier material used for holding a workpiece in a double-side polishing apparatus, wherein the carrier material comprises:
A resin made of a thermosetting resin or a thermoplastic resin, a sheet made of a metal sheet or a ceramic sheet, or at least a material selected from metal fibers, ceramic fibers, glass fibers, carbon fibers, and organic synthetic fibers. A thin plate of a composite material reinforced by a laminate obtained by laminating one cloth, wherein the thermosetting resin or the thermoplastic resin internally contains colloidal metal oxide fine particles and / or inorganic fine powder. A carrier material characterized by being made. 2. The carrier material according to claim 1, wherein the metal sheet and the ceramic sheet are porous having through holes. 3. A carrier material used for holding a work piece in a double-side polishing apparatus, wherein the carrier material comprises:
Laminate a resin made of a thermosetting resin or a thermoplastic resin, and fabric made of organic synthetic fibers into which at least one of colloidal metal oxides, nitrides, carbides, and other inorganic fine particles is added. A carrier material comprising a thin plate of a composite material reinforced with a laminated body. 4. Sheets comprising metal sheets or ceramic sheets, or fabrics comprising at least one material selected from metal fibers, ceramic fibers, glass fibers, carbon fibers and organic synthetic fibers. Impregnated with at least one of a thermosetting resin or a thermoplastic resin prepolymer or precursor in which colloidal metal oxide fine particles and / or inorganic fine powder are mixed and dispersed therein, or a solution or a molten liquid of those polymers Let it be laminated, and press and heat it,
3. The method for producing a carrier material according to claim 1, further comprising molding. 5. The organic synthetic fiber according to claim 3, wherein at least one of colloidal metal oxides, nitrides, carbides and other inorganic fine particles is kneaded into the raw material polymer of said organic synthetic fiber. The fabric made from this organic synthetic fiber is
Carrier characterized by impregnating a thermosetting resin or a prepolymer or precursor of a thermoplastic resin, or a solution in which the polymer is dissolved or melted, laminating a plurality of layers, heating under pressure, and then molding. The method of manufacturing the material.