Base layer, polishing pad including the same and polishing method

Abstract

A polishing pad including a polishing layer and a base layer is provided. Disposed under the polishing layer, the base layer includes a porous inner layer and at least one surface layer. The porous inner layer has an upper surface and a lower surface. The surface layer is disposed on at least one of the upper surface and the lower surface of the porous inner layer. The surface layer has a pore ratio no larger than 0.3%, or is completely non-porous.

1 . A polishing pad, comprising:
 a polishing layer; and   a base layer, disposed under the polishing layer, and comprising:
 a porous inner layer having an upper surface and a lower surface; and 
 at least one surface layer having a pore ratio no larger than 0.3% and disposed on at least one of the upper surface and the lower surface of the porous inner layer. 
   
     
     
         2 . The polishing pad as claimed in  claim 1 , wherein the surface layer is a non-porous surface layer and has a pore ratio of 0%. 
     
     
         3 . The polishing pad as claimed in  claim 2 , wherein the porous inner layer and the non-porous surface layer are manufactured integrally using a same material. 
     
     
         4 . The polishing pad as claimed in  claim 2 , wherein a thickness of the non-porous surface layer is larger than 5 μm. 
     
     
         5 . The polishing pad as claimed in  claim 4 , wherein the thickness of the non-porous surface layer ranges from 8 μm to 35 μm. 
     
     
         6 . The polishing pad as claimed in  claim 2 , wherein a surface roughness of the non-porous surface layer is smaller than 15 μm. 
     
     
         7 . The polishing pad as claimed in  claim 6 , wherein the surface roughness of the non-porous surface layer ranges from 3 μm to 10 μm. 
     
     
         8 . The polishing pad as claimed in  claim 2 , wherein a pore size distribution of pores in the porous inner layer ranges from 10 μm to 400 μm. 
     
     
         9 . The polishing pad as claimed in  claim 8 , wherein an average pore size of the pores in the porous inner layer ranges from 100 μm to 250 μm. 
     
     
         10 . The polishing pad as claimed in  claim 1 , wherein the base layer is manufactured using low density polyethylene or a mixture of low density polyethylene and ethylene vinyl acetate. 
     
     
         11 . The polishing pad as claimed in  claim 2  further comprising an adhesive layer at least disposed between the polishing layer and the base layer or between the base layer and a polishing machine. 
     
     
         12 . The polishing pad as claimed in  claim 11 , wherein a shear stress resistance maintenance time test is performed after the base layer and the adhesive layer are adhered; when a shear stress is applied to the non-porous surface layer, the base layer and the adhesive layer have a first maintenance time therebetween; when the shear stress is applied to the porous inner layer, the base layer and the adhesive layer have a second maintenance time therebetween; the first maintenance time is at least 20% longer than the second maintenance time. 
     
     
         13 . The polishing pad as claimed in  claim 2 , wherein the non-porous surface layer comprises a non-porous surface layer underwent a plasma treatment. 
     
     
         14 . A base layer adapted for underlying a polishing layer of a polishing pad, the base layer comprising:
 a porous inner layer having an upper surface and a lower surface; and   a surface layer having a pore ratio no larger than 0.3% and disposed on at least one of the upper surface and the lower surface of the porous inner layer.   
     
     
         15 . The base layer as claimed in  claim 14 , wherein the surface layer is a non-porous surface layer and has a pore ratio of 0%. 
     
     
         16 . The base layer as claimed in  claim 15 , wherein the porous inner layer and the non-porous surface layer are manufactured integrally using a same material. 
     
     
         17 . The base layer as claimed in  claim 15 , wherein a thickness of the non-porous surface layer is larger than 5 μm. 
     
     
         18 . The base layer as claimed in  claim 17 , wherein the thickness of the non-porous surface layer ranges from 8 μm to 35 μm. 
     
     
         19 . The base layer as claimed in  claim 15 , wherein a surface roughness of the non-porous surface layer is smaller than 15 μm. 
     
     
         20 . The base layer as claimed in  claim 19 , wherein the surface roughness of the non-porous surface layer ranges from 3 μm to 10 μm. 
     
     
         21 . The base layer as claimed in  claim 15 , wherein a pore size distribution of pores in the porous inner layer ranges from 10 μm to 400 μm. 
     
     
         22 . The base layer as claimed in  claim 21 , wherein an average pore size of the pores in the porous inner layer ranges from 100 μm to 250 μm. 
     
     
         23 . The base layer as claimed in  claim 14 , wherein the base layer is manufactured using low density polyethylene or a mixture of low density polyethylene and ethylene vinyl acetate. 
     
     
         24 . The base layer as claimed in  claim 15 , wherein the non-porous surface layer comprises a non-porous surface layer underwent a plasma treatment. 
     
     
         25 . A polishing method adapted to polish a substrate, the method comprising:
 providing a polishing pad;   applying a pressure on the substrate to press the substrate on the polishing pad; and   providing a relative motion between the substrate and the polishing pad, wherein the polishing pad comprises:
 a polishing layer; and 
 a base layer, disposed under the polishing layer, and comprising:
 a porous inner layer having an upper surface and a lower surface; 
 
 and 
 at least one surface layer having a pore ratio no larger than 0.3% and disposed on at least one of the upper surface and the lower surface of the porous inner layer. 
   
     
     
         26 . The polishing method as claimed in  claim 25 , wherein the surface layer is a non-porous surface layer and has a pore ratio of 0%. 
     
     
         27 . The polishing method as claimed in  claim 26 , wherein the porous inner layer and the non-porous surface layer are manufactured integrally using a same material. 
     
     
         28 . The polishing method as claimed in  claim 26 , wherein a thickness of the non-porous surface layer is larger than 5 μm. 
     
     
         29 . The polishing method as claimed in  claim 26 , wherein a surface roughness of the non-porous surface layer is smaller than 15 μm. 
     
     
         30 . The polishing method as claimed in  claim 26 , wherein a pore size distribution of pores in the porous inner layer ranges from 10 μm to 400 μm. 
     
     
         31 . The polishing method as claimed in  claim 25 , wherein the base layer is manufactured using low density polyethylene or a mixture of low density polyethylene and ethylene vinyl acetate. 
     
     
         32 . The polishing method as claimed in  claim 26 , wherein the non-porous surface layer comprises a non-porous surface layer underwent a plasma treatment.