Chemical mechanical polishing pad structure minimizing trapped air and polishing fluid intrusion

Abstract

A polishing pad is attachable to a platen to minimize trapped air and polishing fluid intrusion. The pad comprises a polishing layer having a polishing surface on a first end of the pad and a polishing layer peripheral edge extending away from the polishing surface; a gas impermeable attaching layer defines an attachment surface for securing the pad to the platen at an opposed second end of the pad, the attaching layer having an attaching layer peripheral edge extending away from the attachment surface, wherein a peripheral edge of the pad extends from the polishing surface to the attaching surface formed of the peripheral edges of each pad layer; and a plurality of openings extending through the attaching layer. During pad attachment, trapped air flows through the attaching layer openings and out of the peripheral edge of the pad at a position spaced from the attaching layer peripheral edge.

1 . A polishing pad configured to be removably attached to a platen, the pad comprising:
 a polishing layer having a polishing surface on a first end of the polishing pad and a polishing layer peripheral edge extending away from the polishing surface;   a gas impermeable attaching layer defining an attachment surface for securing the polishing pad to a platen at a second end of the polishing pad which is opposed from the first end, the attaching layer having an attaching layer peripheral edge extending away from the attachment surface, wherein a peripheral edge of the pad extends from the polishing surface to the attaching surface formed of the peripheral edges of each layer of the pad; and   a plurality of openings extending through the attaching layer, whereby trapped air during pad attachment can flow through the openings in the attaching layer and out of the peripheral edge of the pad at a position spaced from the attaching layer peripheral edge.   
     
     
         2 . The polishing pad of  claim 1  wherein the pad layer adjacent the attaching layer is gas permeable and wherein the openings terminate before the polishing surface. 
     
     
         3 . The polishing pad of  claim 2  further including a gas-permeable sub-pad layer adjacent the attaching layer and the sub-pad layer having a sub-pad layer peripheral edge. 
     
     
         4 . The polishing pad of  claim 3  further including a gas impermeable barrier layer between the polishing layer and the sub-pad layer, whereby the trapped air flows out of the sub-pad layer peripheral edge. 
     
     
         5 . The polishing pad of  claim 1  wherein the plurality of openings form a pattern of openings on the attaching surface that is less than about ½″ between openings. 
     
     
         6 . The polishing pad of  claim 5  wherein the pattern of openings on the attaching surface is about ¼″ between openings which are formed of holes about 0.02″ in diameter. 
     
     
         7 . The polishing pad of  claim 5  wherein the pattern of openings are formed by a series of circular holes terminating before the polishing surface. 
     
     
         8 . The polishing pad of  claim 5  wherein the pattern of openings are formed by a series of elongated slits terminating before the polishing surface. 
     
     
         9 . The polishing pad of  claim 1  wherein the pad layer adjacent the attaching layer is gas impermeable and further including a plurality of channels extending across the pad layer adjacent the attaching layer to the peripheral edge of the pad layer adjacent the attaching layer, wherein each opening through the attaching layer is aligned with at least one channel, whereby the trapped air flows out of the peripheral edge of the pad layer adjacent to the attaching layer. 
     
     
         10 . The polishing pad of  claim 9  wherein the plurality of openings form a pattern of openings on the attaching surface that is less than about ¾ between openings. 
     
     
         11 . A polishing pad configured to be removably attached to a platen, the pad comprising:
 a polishing layer having a polishing surface on a first end of the polishing pad and a polishing layer peripheral edge extending away from the polishing surface;   an attaching layer defining an attachment surface for securing the polishing pad to a platen at a second end of the polishing pad which is opposed from the first end, the attaching layer having an attaching layer peripheral edge extending away from the attachment surface,   a gas-permeable sub-pad layer adjacent the attaching layer and the sub-pad layer having a sub-pad layer peripheral edge, wherein a peripheral edge of the pad extends from the polishing surface to the attaching surface formed of the peripheral edges of each layer of the pad; and   a plurality of openings extending through the attaching layer and terminating before extending through the sub-pad layer, whereby trapped air during pad attachment can flow through the openings in the attaching layer and out of the peripheral edge of the pad at a position spaced from the attaching layer peripheral edge.   
     
     
         12 . The polishing pad of  claim 11  further including a gas impermeable barrier layer between the polishing layer and the sub-pad layer, whereby the trapped air flows out of the sub-pad layer peripheral edge. 
     
     
         13 . The polishing pad of  claim 11  wherein the plurality of openings form a pattern of openings on the attaching surface that is less than about ¾″ between openings. 
     
     
         14 . The polishing pad of  claim 13  wherein the pattern of openings on the attaching surface is less than about ½″ between openings. 
     
     
         15 . The polishing pad of  claim 13  wherein the pattern of openings on the attaching surface is about ¼″ between openings which are formed of holes about 0.02″ in diameter. 
     
     
         16 . The polishing pad of  claim 13  wherein the pattern of openings are formed by a series of circular holes. 
     
     
         17 . The polishing pad of  claim 13  wherein the pattern of openings are formed by a series of elongated slits. 
     
     
         18 . A polishing pad configured to be removably attached to a platen, the pad comprising:
 a polishing layer having a polishing surface on a first end of the polishing pad and a polishing layer peripheral edge extending away from the polishing surface;   a gas impermeable attaching layer defining an attachment surface for securing the polishing pad to a platen at a second end of the polishing pad which is opposed from the first end, the attaching layer having an attaching layer peripheral edge extending away from the attachment surface, wherein a peripheral edge of the pad extends from the polishing surface to the attaching surface formed of the peripheral edges of each layer of the pad;   sub-pad layer adjacent the attaching layer and the sub-pad layer having a sub-pad layer peripheral edge, wherein a peripheral edge of the pad extends from the polishing surface to the attaching surface formed of the peripheral edges of each layer of the pad; and   a plurality of openings extending through the attaching layer and terminating before extending through the sub-layer layer, whereby trapped air during pad attachment can flow through the openings in the attaching layer and out of the peripheral edge of the pad at a position spaced from the attaching layer peripheral edge.   
     
     
         19 . The polishing pad of  claim 18  wherein the sub-pad layer adjacent the attaching layer is gas impermeable and further including a plurality of channels extending across the sub-pad layer to the sub-pad layer peripheral edge, wherein each opening through the attaching layer is aligned with at least one channel, whereby the trapped air flows out of the peripheral edge of the sub-pad layer adjacent to the attaching layer. 
     
     
         20 . The polishing pad of  claim 18  wherein the plurality of openings form a pattern of openings on the attaching surface that is less than about ¾″ between openings.