Polishing pad and chemical mechanical polishing apparatus comprising the same

Abstract

A polishing pad for use in chemically mechanically polishing a semiconductor substrate enhances the uniformity of the rate at which material is removed from the surface of the semiconductor substrate, thereby ensuring the reproducibility of the chemical mechanical polishing process. The polishing pad has main grooves that divide an upper portion of the pad into a plurality of cells. At least one of the cells includes a land portion and a grooved portion substantially enclosed by the land portion. A respective slurry hole extends through the pad to the grooved portion such that slurry supplied through the slurry hole feeds into the grooved portion but is impeded by the land portion from flowing outwardly of the cell.

1 . A polishing pad for use in chemical mechanical polishing, the polishing pad having an upper surface, 
 main grooves extending in the upper surface and separating an upper portion of the pad into a plurality of cells, wherein the main grooves delimit the cells,    at least one of the cells consisting of a land portion, and a grooved portion, the grooved portion being entirely enclosed by the land portion and defined by at least one groove extending in the upper surface of the pad within the cell, each said at least one groove having a bottom delimited by a surface of the pad which is located intermediate the major upper and lower surfaces of the pad, and    a respective slurry hole extending through the pad to the grooved portion of each said at least one of the cells, whereby slurry supplied through the slurry hole towards the upper surface of the pad will feed into the at least one groove and will be impeded by the land portion from spreading outwardly of the cell.    
   
   
       2 . The polishing pad of  claim 1 , wherein the at least one groove includes a first major groove intersecting the location to which the respective slurry hole extends in the cell.  
   
   
       3 . The polishing pad of  claim 2 , wherein the first major groove extends symmetrically with respect to the slurry hole.  
   
   
       4 . The polishing pad of  claim 2 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have the same length.  
   
   
       5 . The polishing pad of  claim 2 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have different lengths.  
   
   
       6 . A chemical mechanical polishing apparatus comprising: 
 a platen having a slurry flow passageway extending therein and open at an upper surface thereof;    a slurry supply unit connected to said slurry flow passageway;    a polishing pad disposed on the upper surface of said platen, said polishing pad having an upper surface,    main grooves extending in the upper surface and separating an upper portion of the pad into a plurality of cells, wherein the main grooves delimit the cells,    at least one of the cells consisting of a land portion, and a grooved portion, the grooved portion being entirely enclosed by the land portion and defined by at least one groove extending in the upper surface of the pad within the cell, each said at least one groove having a bottom delimited by a surface of the pad which is located intermediate the major upper and lower surfaces of the pad, and    a respective slurry hole extending through the pad to the grooved portion of each said at least one of the cells and communicating with the slurry flow passageway of the platen, whereby slurry supplied through the slurry hole towards the upper surface of the pad will feed into the at least one groove and will be blocked by the land portion from spreading outwardly of the cell; and    a polishing head disposed above said platen and operative to force a surface of a substrate to be polished against the polishing pad.    
   
   
       7 . The chemical mechanical polishing apparatus of  claim 6 , wherein the at least one groove of the polishing pad includes a first major groove intersecting the location to which the respective slurry hole extends in the cell.  
   
   
       8 . The chemical mechanical polishing apparatus of  claim 7 , wherein the first major groove extends symmetrically with respect to the slurry hole.  
   
   
       9 . The chemical mechanical polishing apparatus of  claim 7 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have the same length.  
   
   
       10 . The polishing pad of  claim 7 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have different lengths.  
   
   
       11 . A polishing pad for use in chemical mechanical polishing, the polishing pad having an upper surface, 
 main grooves extending in the upper surface and separating an upper portion of the pad into a plurality of cells, wherein the main grooves delimit the cells,    at least one of the cells consisting of a land portion, and a grooved portion, the grooved portion being substantially enclosed by the land portion and defined by at least one groove extending in the upper surface of the pad within the cell,    each said at least one groove having a bottom delimited by a surface of the pad which is located intermediate the major upper and lower surfaces of the pad, and including a first major groove extending across the location to which the respective slurry hole extends in the cell so as to intersect said location, and wherein the first major groove is symmetrical with respect to the slurry hole, and    a respective slurry hole extending through the pad to the grooved portion of each said at least one of the cells, whereby slurry supplied through the slurry hole towards the upper surface of the pad will feed into the at least one groove and will be impeded by the land portion from spreading outwardly of the cell.    
   
   
       12 . The polishing pad of  claim 6 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have the same length.  
   
   
       13 . The polishing pad of  claim 6 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have different lengths.  
   
   
       14 . A chemical mechanical polishing apparatus comprising: 
 a platen having a slurry flow passageway extending therein and open at an upper surface thereof;    a slurry supply unit connected to said slurry flow passageway;    a polishing pad disposed on the upper surface of said platen, said polishing pad having an upper surface,    main grooves extending in the upper surface and separating an upper portion of the pad into a plurality of cells, wherein the main grooves delimit the cells,    at least one of the cells consisting of a land portion, and a grooved portion, the grooved portion being substantially enclosed by the land portion and defined by at least one groove extending in the upper surface of the pad within the cell,    each said at least one groove having a bottom delimited by a surface of the pad which is located intermediate the major upper and lower surfaces of the pad, and including a first major groove extending across the location to which the respective slurry hole extends in the cell so as to intersect said location, and wherein the first major groove is symmetrical with respect to the slurry hole, and    a respective slurry hole extending through the pad to the grooved portion of each said at least one of the cells and communicating with the slurry flow passageway of the platen, whereby slurry supplied through the slurry hole towards the upper surface of the pad will feed into the at least one groove and will be blocked by the land portion from spreading outwardly of the cell; and    a polishing head disposed above said platen and operative to force a surface of a substrate to be polished against the polishing pad.    
   
   
       15 . The chemical mechanical polishing apparatus of  claim 14 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have the same length.  
   
   
       16 . The chemical mechanical polishing apparatus of  claim 14 , wherein at least two of the cells consist of a respective said land portion and a respective said grooved portion, and the first major grooves extending in the upper surface of the pad within at least two of said cells have different lengths.