Polishing pad and polishing apparatus

Abstract

A polishing pad includes a polishing layer including a polishing surface, and a sealed layer including a support surface, wherein the polishing layer and the sealed layer are sequentially ordered, and wherein the polishing surface is provided as a front surface and the support surface is provided as a back surface. The support surface has a water contact angle of 90° or more. The water contact angle of the polishing surface is smaller than the water contact angle of the support surface. The polishing pad is formed of a resin molded body.

What is claimed is: 
     
         1 . A polishing pad comprising:
 a polishing layer including a polishing surface; and   a sealed layer including a support surface,   wherein the polishing layer and the sealed layer are sequentially ordered,   wherein the polishing surface is provided as a front surface and the support surface is provided as a back surface,   wherein the support surface has a water contact angle of 90° or more,   wherein the water contact angle of the polishing surface is smaller than the water contact angle of the support surface, and   wherein the polishing pad is formed of a resin molded body.   
     
     
         2 . The polishing pad according to  claim 1 , wherein the water contact angle of the support surface is 150° or less. 
     
     
         3 . The polishing pad according to  claim 1 , wherein the sealed layer comprises fluororesin particles. 
     
     
         4 . The polishing pad according to  claim 3 , wherein a content of the fluororesin particles in the sealed layer is in a range from 20% by mass to 50% by mass. 
     
     
         5 . The polishing pad according to  claim 3 , wherein the fluororesin particles comprise polytetrafluoroethylene. 
     
     
         6 . The polishing pad according to  claim 1 , wherein the polishing layer contains hydrophilic metal oxide particles. 
     
     
         7 . The polishing pad according to  claim 6 , wherein the metal oxide particles comprise at least one of silica and alumina. 
     
     
         8 . The polishing pad according to  claim 6 , wherein a content of the metal oxide particles in the polishing layer is in a range from 20% by mass to 50% by mass. 
     
     
         9 . The polishing pad according to  claim 1 , wherein the resin molded body comprises a foam including cells, and the cells each have a flat shape in a thickness direction of the polishing pad. 
     
     
         10 . The polishing pad according to  claim 9 , wherein a length of the flat shape in a thickness direction of each of the cells in the polishing layer and the sealed layer is less than or equal to a thickness of the polishing layer and a thickness of the sealed layer. 
     
     
         11 . The polishing pad according to  claim 9 , wherein an average cell diameter of the cells in the polishing surface is in a range from 50 μm to 300 μm. 
     
     
         12 . The polishing pad according to  claim 1 , wherein the polishing pad has a water vapor permeability of 25 g/m 2 ·24 hr or less. 
     
     
         13 . The polishing pad according to  claim 1 , wherein the polishing pad contains polyurethane as a main component. 
     
     
         14 . The polishing pad according to  claim 1 , wherein a thickness of the polishing pad is in a range from 0.3 mm to 2.0 mm. 
     
     
         15 . A polishing apparatus configured to polish a workpiece placed on a polishing surface of a polishing pad, the polishing apparatus comprising:
 a base;   the polishing pad fixed to the base; and   a fluid storage portion configured to store a fluid to apply a pressure to the polishing pad from the sealed layer side,
 wherein the polishing pad includes 
 a polishing layer including the polishing surface; and 
 a sealed layer including a support surface, 
 wherein the polishing layer and the sealed layer are sequentially ordered, 
 wherein the polishing surface is provided as a front surface and the support surface is provided as a back surface, 
 wherein the support surface has a water contact angle of 90° or more, 
 wherein the water contact angle of the polishing surface is smaller than the water contact angle of the support surface, and 
 wherein the polishing pad is formed of a resin molded body. 
   
     
     
         16 . A polishing pad comprising:
 a polishing surface;   a first region;   a second region; and   a sealed layer,   wherein the polishing surface, the first region, the second region, and the sealed layer are sequentially ordered,   wherein the first region includes a first cell and has a first hardness,   wherein the second region includes a second cell and has a second hardness lower than the first hardness,   wherein an average cell density in the sealed layer is lower than an average cell density in the first region and the second region, and   wherein the polishing pad is formed of a resin molded body.   
     
     
         17 . The polishing pad according to  claim 16 , wherein the polishing pad has a gas permeability of 50 ml/m 2 ·24 hr-atm or less. 
     
     
         18 . The polishing pad according to  claim 16 , wherein the average cell density in the second region is higher than the average cell density in the first region. 
     
     
         19 . The polishing pad according to  claim 18 ,
 wherein the average cell density in the first region is in a range from 10% to 40%, and   wherein the average cell density in the second region is in a range from 40% to 80%.   
     
     
         20 . The polishing pad according to  claim 16 , wherein an average equivalent circle diameter of the second cell is greater than an average equivalent circle diameter of the first cell. 
     
     
         21 . The polishing pad according to  claim 16 , wherein an average cell density in the sealed layer is 10% or less. 
     
     
         22 . The polishing pad according to  claim 16 , wherein a hardness of the sealed layer is higher than the first hardness and the second hardness. 
     
     
         23 . The polishing pad according to  claim 16 , wherein the polishing pad contains polyurethane as a main component. 
     
     
         24 . The polishing pad according to  claim 16 , wherein a thickness of the polishing pad in a direction in which the polishing surface, the first region, the second region, and the sealed layer are sequentially ordered is in a range from 0.3 mm to 2.0 mm. 
     
     
         25 . The polishing pad according to  claim 16 , wherein a thickness of the second region is greater than a thickness of the first region and a thickness of the sealed layer.