Polishing pad and method of polishing a semiconductor wafer

Abstract

A polishing pad, a polishing laminated pad and a semiconductor wafer polishing method all of which prevent a leak of slurry from the gap between a polishing substrate and a reduction in polishing efficiency caused by a scratched and a window member and enable the optical detection of the polishing end point to be carried out efficiently. The polishing pad comprises a polishing substrate having a through hole extending from the front side to the rear side and a light transmitting member arranged in the through hole, and the outer wall of the above light transmitting member and the inner wall of the though hole opposite to the outer wall are bonded together with a photocurable adhesive such as a polyurethane(meth)acrylate to fix the above light transmitting member in the through hole.

What is claimed is:  
     
         1 . A polishing pad comprising a polishing substrate having a through hole extending from its polishing surface to the opposite surface and a light transmitting member arranged in the through hole, said light transmitting member being fixed in the through hole by bonding the outer wall of the light transmitting member to the inner wall of the through hole opposed to the outer wall with a photocured adhesive layer.  
     
     
         2 . The polishing pad of  claim 1 , wherein a film is formed to cover the surface opposite to the polishing surface of the polishing pad of the light transmitting member, made of the same material as the photocured adhesive layer and integrated with the photocured adhesive layer.  
     
     
         3 . The polishing pad of  claim 1 , wherein the light transmitting member comprises a water-insoluble matrix material (A) and a water-soluble substance (B) dispersed in the water-insoluble matrix material (A), and the content of the water-soluble substance (B) is 0.1 to 90 vol % based on 100 vol % of the total of the water-insoluble matrix material (A) and the water-soluble substance (B).  
     
     
         4 . The polishing pad of  claim 1 , wherein at least part of the water-insoluble matrix material (A) is a crosslinked polymer.  
     
     
         5 . The polishing pad of  claim 4 , wherein the crosslinked polymer is crosslinked 1,2-polybutadiene.  
     
     
         6 . The polishing pad of  claim 1 , wherein the light transmitting member has a transmittance at a wavelength between 400 nm and 800 nm of 0.1% or more or an integrated transmittance at a wavelength between 400 nm and 800 nm of 0.1% or more when it is 2 mm in thickness.  
     
     
         7 . The polishing pad of  claim 1 , wherein the photocured adhesive layer comprises a photocured product of a photocured adhesive layer, and the viscosity at 25° C. of the photocured adhesive layer is 1,000 to 100,000 mPa.s.  
     
     
         8 . The polishing pad of  claim 1 , wherein the photocurable adhesive comprises a polyurethane(meth)acrylate.  
     
     
         9 . The polishing pad of  claim 1 , wherein the sectional form of the through hole is square, rectangular or circular.  
     
     
         10 . A polishing laminated pad comprising the polishing pad of  claim 1  and a base layer having light transmission properties formed on the surface opposite to the polishing surface of the polishing pad.  
     
     
         11 . A method of polishing a semiconductor wafer with a polishing pad, wherein the polishing pad of  claim 1  is used and the polishing end point of a semiconductor wafer is detected by an optical end-point detection device through the light transmitting member of the polishing pad or the polishing laminated pad.  
     
     
         12 . A method of polishing a semiconductor wafer with a polishing pad, wherein the polishing laminate pad of  claim 10  is used and the polishing end point of a semiconductor wafer is detected by an optical end-point detection device through the light transmitting member of the polishing pad or the polishing laminated pad.