Polishing pads and systems and methods of making and using the same

Abstract

A polishing pad includes a polishing layer having a first major surface and a second major surface opposite the first major surface. The polishing pad further includes a subpad, which is coupled to the polishing layer, and has a first major surface and a second major surface opposite the first major surface. At least 50% of the subpad, based on the total surface area of the first major surface of the subpad, is optically transparent.

What is claimed is: 
     
         1 ) A polishing pad comprising:
 a polishing layer having a first major surface and a second major surface opposite the first major surface;   a subpad having a first major surface and a second major surface opposite the first major surface,   wherein the subpad is coupled to the polishing layer; and   wherein at least 50% of the subpad, based on the total surface area of the first major surface of the subpad, is optically transparent.   
     
     
         2 ) The polishing pad of  claim 1 , wherein at least 50% of the polishing layer, based on the total surface area of the first major surface of the polishing pad, is optically transparent. 
     
     
         3 ) The polishing pad of  claim 2 , wherein at least 50% of the optically transparent region of the subpad overlays the optically transparent region of the polishing pad. 
     
     
         4 ) The polishing pad of  claim 3 , wherein the polishing pad is optically transparent in the region of the subpad that overlays the optically transparent region of the polishing pad. 
     
     
         5 ) The polishing pad of  claim 4 , wherein the subpad has a Young's Modulus of between 4000 kPa and 100 kPa, between 3000 kPa and 200 kPa, or between 300 and 2000 kPa. 
     
     
         6 ) The polishing pad of  claim 4 , wherein the subpad has a Shore A hardness of between 5 and 70. 
     
     
         7 ) The polishing pad of  claim 4 , wherein the subpad is elasctically deformable. 
     
     
         8 ) The polishing pad of  claim 4 , wherein the subpad has a relaxation modulus of less than 40%. 
     
     
         9 ) The polishing pad of  claim 1 , wherein the subpad comprises cavities or voids. 
     
     
         10 ) The polishing pad of  claim 9 , wherein a volume percentage of the voids and cavities is less than about 50. 
     
     
         11 ) The polishing pad of  claim 4 , wherein the subpad has a compressibility at 25% deflection of between 25 and 1000 kPa. 
     
     
         12 ) The polishing pad of  claim 4 , wherein the subpad comprises a polymer having a glass transition below room temperature. 
     
     
         13 ) The polishing pad of  claim 4 , wherein the subpad comprises a polymer and a plasticizer. 
     
     
         14 ) The polishing pad of  claim 4 , wherein the subpad comprises an acrylate or methacrylate resin. 
     
     
         15 ) The polishing pad of  claim 4 , wherein the polishing layer comprises pores and asperities. 
     
     
         16 ) A method of polishing a substrate, the method comprising:
 providing the polishing pad of  claim 4 ;   providing a substrate;   contacting the first major surface of the polishing pad with the substrate;   moving the polishing pad and the substrate relative to one another while maintaining contact between the first major surface of the polishing pad and the substrate.