Polishing apparatus, polishing pad, and polishing method

Abstract

A polishing pad is placed on a polishing apparatus including a polishing platen which is rotatable and on which the polishing pad is placed, a substrate retaining mechanism, and a supplying mechanism for supplying a polishing agent on an upper surface of the polishing pad, the polishing pad having grooves extending from the center of the polishing pad to the outer edge thereof, the groove becoming gradually deeper from the center of the polishing pad toward the outer edge portion thereof so that the depth of the groove is the largest at the outer edge portion, thereby allowing a slurry to be smoothly discharged from the upper surface of the polishing platen.

1 . A polishing pad, having a plurality of grooves extending from center to edge of the polishing pad, wherein the groove has a depth becoming larger from the center of the polishing pad toward edge portion and largest at the edge portion. 
     
     
         2 . A polishing pad as claimed in  claim 1 , wherein the depths of the groove is gradually increased. 
     
     
         3 . A polishing pad as claimed in  claim 1 , wherein the depths of the groove is stepwisely increased. 
     
     
         4 . A polishing pad as claimed in  claim 1 , wherein the plurality of grooves are provided in grid like fashion onto the surface of the polishing pad. 
     
     
         5 . A polishing pad as claimed in  claim 1 , wherein the plurality of grooves are provided onto the surface of the polishing pad radially from the center of the polishing pad. 
     
     
         6 . A polishing pad as claimed in  claim 1 , wherein the plurality of grooves are provided onto the surface of the polishing pad in a form of curved line extending from center to edge of the polishing pad. 
     
     
         7 . A polishing pad as claimed in  claim 1 , wherein the grooves are taper-shape having bottom portions that are narrower than their top portions. 
     
     
         8 . A polishing apparatus, comprising:
 a polishing pad;   a polishing platen which is rotatable and on which the polishing pad is placed;   a substrate retaining mechanism; and   a supplying mechanism for supplying a polishing agent on upper surface of the polishing pad, wherein   the polishing pad has a plurality of grooves extending from center to edge of the polishing pad;   the grooves have a depth gradually becoming larger from the center of the polishing pad toward edge portion and largest at the edge portion.   
     
     
         9 . A method of polishing a substrate, comprising the steps of:
 placing the polishing pad according to  claim 1  on a polishing platen;   retaining the substrate;   pressing the substrate to the polishing pad;   supplying a polishing agent to upper surface of the polishing pad;   rotating the polishing platen; and   rotating the substrate.   
     
     
         10 . A polishing pad comprising a body having a center part and a peripheral part, and a plurality of grooves selectively formed in the body with a first depth at the center part and a second depth at the peripheral part, the first depth being smaller than the second depth. 
     
     
         11 . The pad as claimed in  claim 10 , wherein the first depth is changed stepwisely from the second depth. 
     
     
         12 . The pad as claimed in  claim 10 , wherein the first depth is changed gradually from the second depth.