Polishing apparatus and polishing method

Abstract

A polishing apparatus capable of polishing a substrate while accurately measuring a temperature at a desired measuring point near a surface of the substrate is disclosed. The polishing apparatus includes: a polishing pad having a polishing surface for polishing a substrate; a polishing table supporting the polishing pad; a table motor configured to rotate the polishing table; a polishing head configured to press a surface of the substrate against the polishing surface of the polishing pad; a polishing liquid supply nozzle configured to supply a polishing liquid onto the polishing surface of the polishing pad; and a temperature sensor mounted to the polishing table. The temperature sensor is located so as to move across the surface of the substrate each time the polishing table makes one revolution.

What is claimed is: 
     
         1 . A polishing apparatus comprising:
 a polishing pad having a polishing surface for polishing a substrate;   a polishing table supporting the polishing pad;   a table motor configured to rotate the polishing table;   a polishing head configured to press a surface of the substrate against the polishing surface of the polishing pad;   a polishing liquid supply nozzle configured to supply a polishing liquid onto the polishing surface of the polishing pad; and   a temperature sensor mounted to the polishing table, the temperature sensor being located so as to move across the surface of the substrate each time the polishing table makes one revolution.   
     
     
         2 . The polishing apparatus according to  claim 1 , wherein the temperature sensor is disposed under the polishing pad and can measure a temperature of a lower surface of the polishing pad. 
     
     
         3 . The polishing apparatus according to  claim 2 , wherein the polishing pad has a recess in the lower surface, and a distal end of the temperature sensor lies in the recess. 
     
     
         4 . The polishing apparatus according to  claim 1 , wherein the polishing pad has a through-hole, a distal end of the temperature sensor lies in the through-hole, and the temperature sensor can measure a temperature of the polishing liquid present in the through-hole. 
     
     
         5 . The polishing apparatus according to  claim 1 , further comprising a polishing operation controller configured to determine a polishing end point of the substrate based on an output value of the temperature sensor. 
     
     
         6 . The polishing apparatus according to  claim 1 , wherein the temperature sensor comprises a thermocouple. 
     
     
         7 . The polishing apparatus according to  claim 1 , wherein the temperature sensor comprises a combination of an eddy-current sensor and a sensor target made of a conductive material. 
     
     
         8 . A polishing apparatus comprising:
 a polishing pad having a polishing surface, a bottom surface, and a through-hole extending from the polishing surface to the bottom surface;   a polishing table supporting the polishing pad;   a polishing head configured to press a surface of a substrate against the polishing surface of the polishing pad;   an eddy-current sensor mounted to the polishing table, a distal end of the eddy-current sensor lying in the through-hole of the polishing pad; and   a sensor target disposed in the through-hole of the polishing pad.   
     
     
         9 . The polishing apparatus according to  claim 8 , wherein a relative position between the sensor target and the eddy-current sensor is fixed. 
     
     
         10 . The polishing apparatus according to  claim 8 , further comprising a ferrite disposed in the through-hole of the polishing pad. 
     
     
         11 . The polishing apparatus according to  claim 10 , wherein the ferrite is aligned with the eddy-current sensor. 
     
     
         12 . The polishing apparatus according to  claim 10 , wherein the ferrite is not in contact with the eddy-current sensor and the sensor target. 
     
     
         13 . A polishing method comprising:
 rotating a polishing table supporting a polishing pad having a polishing surface;   pressing a surface of a substrate against the polishing surface of the polishing pad while supplying a polishing liquid onto the polishing surface constituted by an upper surface of the polishing pad; and   obtaining an output value of a temperature sensor which is mounted to the polishing table, while moving the temperature sensor across the surface of the substrate with a rotation of the polishing table.   
     
     
         14 . The polishing method according to  claim 13 , wherein obtaining the output value of the temperature sensor comprising measuring a temperature of a lower surface of the polishing pad by the temperature sensor while moving the temperature sensor across the surface of the substrate with the rotation of the polishing table. 
     
     
         15 . The polishing method according to  claim 13 , wherein obtaining the output value of the temperature sensor comprising measuring a temperature of the polishing liquid, which is present between the substrate and the temperature sensor, by the temperature sensor while moving the temperature sensor across the surface of the substrate with the rotation of the polishing table. 
     
     
         16 . The polishing method according to  claim 13 , further comprising determining a polishing end point of the substrate based on the output value of the temperature sensor.