Polishing pad and method of producing same

Abstract

The present invention relates to a method of producing a polishing pad, comprising steps of: (a) providing a base material comprising a plurality of fibers; said base material having a surface for polishing a substrate; (b) impregnating the surface of the base material with an elastomer solution; (c) curing the elastomer impregnated in the surface of the base material to form a plurality of first continuous pores embedded in the elastomer and fibers; (d) impregnating the surface of the base material and elastomer obtained in the step (c) with a condition polymer solution; and (e) curing the condition polymer impregnated in the surface of the base material and elastomer and partially filling the condition polymer into the first continuous pores to form a plurality of second continuous pores.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a polishing pad for use in a chemical mechanical polishing, and a method for producing the polishing pad. [0003] 2. Description of the Related Art [0004] Chemical mechanical polishing (CMP) is a procedure for planarizing the surface of a substrate with a polishing pad. CMP is generally applied in polishing lens, mirrors, substrates of liquid crystal displays, silicon wafers, and oxidation and / or metal layers on silicon wafers. [0005] U.S. Pat. No. 6,454,634 discloses a polishing pad produced by a method comprising the steps of pouring thermoplastic foam resin in a circular mold to form a casting, skiving the casting into sheets, and mechanically machining macro-channels into the surface of the sheets. The polishing pad comprises a polymeric matrix made of polyurethane and hollow elastic polymeric micropheres are distributed therein. The cell size and distribution in the polishing pad...

AI Technical Summary

Benefits of technology

[0007] One object of the present invention is to provide to a method of producing a polishing pad, comprising the steps of:

[0013] Another object of the present invention is to provide a polishing pad comprising a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of fibers, at least one elastomer and at least one condition polymer, and a plurality of continuous pores are embedded in the fibers, elastomer and condition polymer.

[0014] A further object of the present invention is to provide a method of polishing a substrate comprising using a polishing pad to polish a surface of the substrate, wherein the polishing pad comprises a base material having a surface for polishing the substrate, wherein the surface comprises a plurality of fibers, at least one elastomer and at least one condition polymer, and a plurality of continuous pores are embedded in the fibers, elastomer and condition polymer.

Problems solved by technology

It is difficult to even out the distribution of each component in a mixture for molding in a circular mold.

Furthermore, because of viscoelastic property of polyurethane, a knife used in a skiving step cannot be located on the edge of the sheet precisely and subsequently influences the flatness, size and distribution of the cells.

These factors reduce the batch uniformity when producing the polishing pad, and thus a polishing process involved becomes complicated.

In another aspect, the cells of the polishing pad in this patent are discontinuous for each other, so that polishing fluid cannot flow smoothly and polishing particles cannot diffuse evenly.

Besides, the residues formed during polishing easily stay on the surface of the polishing pad and their removal is poor; as a result, the residues scrap and damage the substrate to be polished.

However, the thermocompression molding step easily leads to uneven space formed between the layers.

As a result, hardness, flatness, compression ratio, elasticity, and recovery ratio of the surface of the polishing pad are all affected.

Besides, the method of producing with the condition at high temperature (such as 300° C.) and high pressure (such as 196 kN / m) chars and hardens the surface of the polishing pad, and then the polishing pad scraps and damages the substrate to be polished.

Furthermore, when producing the polishing pad, migration easily occurs and the polymers cannot be distributed in the sheet-form fiber base evenly.

The factors all reduce the efficiency of polishing.

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