Polishing pad, process for producing the same and method of polishing therewith

Abstract

Provided is a polishing pad comprising a fiber including organic fiber and a matrix resin holding the fiber, wherein at least the organic fiber is exposed on the work material-side surface thereof at least after dressing. The polishing pad suppresses generation of minute polishing scratches on the work material and allows flat polishing at low load. It in also possible to manage the polishing end point of the work material without generation of polishing scratch with its optical detection system monitoring the polishing state of work material. Thus, for example, it is possible to polish substrates under a small load on the interlayer insulating film and give products superior in flatness in semiconductor device manufacturing processes and thus, the polishing pad according to the invention may be used easily in the next-generation dual damascene method.

1 . A polishing pad comprising a fiber including organic fiber and a matrix resin holding the fiber, wherein at least the organic fiber is exposed on the work material-side surface thereof.  
     
     
         2 . A polishing pad comprising a fiber including organic fiber and a matrix resin holding the fiber, wherein at least the organic fiber is exposed on the work material-side surface after dressing treatment.  
     
     
         3 . The polishing pad according to  claim 1  or  2 , wherein the matrix resin contains at least one thermoplastic resin.  
     
     
         4 . The Polishing pad according to  claim 1  or  2 , wherein the matrix resin is a semicrystalline thermoplastic resin.  
     
     
         5 . The polishing pad according to  claim 1  or  2 , wherein an elastomer is dispersed in the matrix resin.  
     
     
         6 . The polishing pad according to  claim 5 , wherein the elastomer has a glass transition point of 0° C. or less.  
     
     
         7 . The polishing pad according to  claim 1  or  2 , wherein the fiber is an aromatic polyamide.  
     
     
         8 . The polishing pad according to  claim 1  or  2 , wherein the polishing pad contains an inorganic fiber in an amount of 1 to 50 wt %.  
     
     
         9 . The polishing pad according to  claim 1  or  2 , wherein the organic fiber has a diameter of 1 mm or less.  
     
     
         10 . The polishing pad according to  claim 1  or  2 , wherein the organic fiber has a length of 1 cm or less.  
     
     
         11 . The polishing pad according to  claim 1  or  2 , wherein polishing particles are held by the organic fiber exposed on the work material-side surface.  
     
     
         12 . The polishing pad according to  claim 1  or  2 , wherein the maximum length of the exposed organic fiber is 0.1 mm or less.  
     
     
         13 . The polishing pad according to  claim 12 , wherein the exposed organic fiber is a polyester fiber.  
     
     
         14 . The polishing pad according to  claim 12 , wherein a chopped polyester fiber is dispersed in the matrix resin.  
     
     
         15 . The polishing pad according to  claim 12 , wherein a polyester nonwoven fabric is laminated in the matrix resin.  
     
     
         16 . The polishing pad according to and  claim 1  or  2  that is useful for optical detection of the polishing end point during polishing of the work material surface, wherein the polishing pad contains a substantially non-foam matrix resin containing an organic fiber in an amount of 1 to 20 wt %, has the functions of transporting and retaining polishing slurry particles, and allows transmission of a light having a wavelength in the range of 190 to 3,500 nm.  
     
     
         17 . The polishing pad according to  claim 1  or  2  that is useful for optical detection of the polishing end point during polishing of the work material surface, wherein the polishing pad contains a region transmitting a light having a wavelength in the range of 190 to 3,500 nm that is made of a substantially non-foam matrix resin containing an organic fiber in an amount of 1 to 20 wt % and has the functions of transporting and retaining polishing slurry particles.  
     
     
         18 . The polishing pad according to  claim 16 , wherein the organic fiber is an aramide fiber  
     
     
         19 . A method for producing a polishing pad for use as attached to a polishing table for flattening a work material's polishing plane, comprising a step of obtaining a mixture of a fiber including organic fiber and a matrix composition containing a thermoplastic resin by blending, a step of palletizing or tabletizing the mixture, and a step of molding the pellet or tablet into a plate or a sheet shape by extrusion or injection molding.  
     
     
         20 . A method for producing a polishing pad for use as attached to a polishing table for flattening a work material's polishing plane, comprising a step of impregnating a fibrous base material containing organic fiber with a matrix resin composition to form a fibrous resin-impregnated sheet-shaped base material. and a step of laminating fibrous sheet-shaped base materials including the fibrous resin-impregnated sheet-shaped base material and molding the laminate with heating and pressure.  
     
     
         21 . The method for producing a polishing pad according to  claim 19  or  20 , further including a step of exposing the fiber on the surface.  
     
     
         22 . A polishing method for polishing a work material's polishing plane, comprising polishing a work material pressing the polishing plane of the work material to the organic fiber-exposed face of the polishing pad according to  claim 1  or  2 , and sliding the work material and the pad relatively while supplying a polishing slurry between the work material's polishing plane and the polishing pad.  
     
     
         23 . The polishing method for polishing a work material's polishing plane according to  claim 22 , wherein the work material polishing plane is a laminate of a conductor layer as well as a copper layer formed on an insulation layer having a dielectric constant of 2.7 or less on which wiring and trenches are found.  
     
     
         24 . A polishing method for detecting the polishing end point optically by using the polishing pad according to  claim 16.