Polishing apparatus and polishing method

Abstract

A polishing apparatus according to an embodiment includes a polishing table; a polishing pad provided on the polishing table; a first rotating mechanism configured to rotate the polishing table on a first rotation axis; a substrate holding unit configured to hold a substrate and press the substrate against the polishing pad; a second rotating mechanism configured to rotate the substrate holding unit on a second rotation axis; and a tilting mechanism configured to change an angle between the first rotation axis and the second rotation axis. In the apparatus, the circumferential edge of the substrate is always kept inside the circumferential edge of the polishing pad during polishing of the substrate.

What is claimed is: 
     
         1 . A polishing apparatus comprising:
 a polishing table;   a polishing pad provided on the polishing table;   a first rotating mechanism configured to rotate the polishing table on a first rotation axis;   a substrate holding unit configured to hold a substrate and press the substrate against the polishing pad;   a second rotating mechanism configured to rotate the substrate holding unit on a second rotation axis; and   a tilting mechanism configured to change an angle between the first rotation axis and the second rotation axis,   wherein a circumferential edge of the substrate is always kept inside a circumferential edge of the polishing pad during polishing of the substrate.   
     
     
         2 . The polishing apparatus according to  claim 1 , wherein a relative position of the first rotation axis and the second rotation axis is fixed during polishing of the substrate. 
     
     
         3 . The polishing apparatus according to  claim 1 , wherein the tilting mechanism changes the angle within a range of 0° to 5°. 
     
     
         4 . The polishing apparatus according to  claim 1 , wherein the tilting mechanism changes an inclination of the second rotation axis. 
     
     
         5 . The polishing apparatus according to  claim 1 , further comprising: a control unit configured to control the tilting mechanism and change the angle during polishing of the substrate. 
     
     
         6 . The polishing apparatus according to  claim 1 , wherein the first rotating mechanism and the second rotating mechanism rotate the polishing table and the substrate holding unit, respectively, in one direction. 
     
     
         7 . A polishing method comprising:
 rotating a polishing pad on a first rotation axis; and   pressing a substrate rotating on a second rotation axis tilted with respect to the first rotation axis, against the polishing pad to polish the substrate while always keeping a circumferential edge of the substrate inside a circumferential edge of the polishing pad.   
     
     
         8 . The polishing method according to  claim 7 , wherein an angle between the first rotation axis and the second rotation axis is more than 0° and equal to or less than 5°. 
     
     
         9 . The polishing method according to  claim 7 , wherein the angle between the first rotation axis and the second rotation axis is changed during polishing of the substrate. 
     
     
         10 . The polishing method according to  claim 7 , wherein the polishing table and the substrate holding unit are rotated in one direction.