Polishing apparatus

Abstract

A polishing apparatus includes a table rotating motor configured to rotate a polishing table about its own axis, a top ring rotating motor configured to rotate a top ring about its own axis, a dresser configured to dress a polishing pad, and a pad-height measuring device configured to measure a height of the polishing pad. The polishing apparatus also includes a diagnostic device configured to calculate an amount of wear of the polishing pad from the height of the polishing pad and to determine the end of a life of the polishing pad based on the amount of the wear of the polishing pad, the torque or current of the table rotating motor, and the torque or current of the top ring rotating motor.

1 - 28 . (canceled) 
     
     
         29 . A polishing apparatus comprising:
 a polishing table for supporting a polishing pad;   a top ring configured to press a substrate against a polishing surface of the polishing pad;   a dresser configured to dress the polishing surface of the polishing pad;   a pad-height measuring device configured to measure a height of the polishing pad; and   a diagnostic device configured to monitor the height of the polishing pad and a frictional force acting between the polishing pad and the substrate,   wherein said diagnostic device is configured to calculate an amount of wear of the polishing pad from the height of the polishing pad and to diagnose a condition of the polishing surface of the polishing pad based on the amount of the wear of the polishing pad and on a change in the frictional force.   
     
     
         30 . The polishing apparatus according to  claim 29 , wherein said diagnostic device is configured to determine an end of a life of the polishing pad based on a result of the diagnosis of the condition of the polishing surface. 
     
     
         31 . The polishing apparatus according to  claim 29 , further comprising:
 a film-thickness measuring device configured to measure a film thickness of the substrate and to evaluate a surface flatness of the substrate.   
     
     
         32 . The polishing apparatus according to  claim 29 , wherein said diagnostic device is configured to diagnose the condition of the polishing surface of the polishing pad based on the amount of the wear of the polishing pad and on the change in the frictional force that occurs during polishing of a plurality of substrates. 
     
     
         33 . A polishing apparatus comprising:
 a polishing table for supporting a polishing pad;   a top ring configured to press a substrate against a polishing surface of the polishing pad;   a dresser configured to dress the polishing surface of the polishing pad;   a pad-height measuring device configured to measure a height of the polishing pad; and   a diagnostic device configured to monitor the height of the polishing pad and a polishing rate of the substrate,   wherein said diagnostic device is configured to calculate an amount of wear of the polishing pad from the height of the polishing pad and to diagnose a condition of the polishing surface of the polishing pad based on the amount of the wear of the polishing pad and on a change in the polishing rate.   
     
     
         34 . The polishing apparatus according to  claim 33 , wherein said diagnostic device is configured to determine an end of a life of the polishing pad based on a result of the diagnosis of the condition of the polishing surface. 
     
     
         35 . The polishing apparatus according to  claim 33 , further comprising:
 a film-thickness measuring device configured to measure a film thickness of the substrate and to evaluate a surface flatness of the substrate.   
     
     
         36 . A polishing apparatus comprising:
 a polishing table for supporting a polishing pad;   a top ring configured to press a substrate against a polishing surface of the polishing pad;   a dresser configured to dress the polishing surface of the polishing pad; and   a diagnostic device configured to monitor a thickness of the polishing pad and a frictional force acting between the polishing pad and the substrate,   wherein said diagnostic device is configured to diagnose a condition of the polishing surface of the polishing pad based on a change in the thickness of the polishing pad and on a change in the frictional force.   
     
     
         37 . The polishing apparatus according to  claim 36 , wherein said diagnostic device is configured to diagnose the condition of the polishing surface of the polishing pad based on the change in the thickness of the polishing pad and on the change in the frictional force that occurs during polishing of a plurality of substrates. 
     
     
         38 . The polishing apparatus according to  claim 36 , wherein said diagnostic device is configured to determine an end of a life of the polishing pad based on a result of the diagnosis of the condition of the polishing surface. 
     
     
         39 . A polishing apparatus comprising:
 a polishing table for supporting a polishing pad;   a top ring configured to press a substrate against a polishing surface of the polishing pad;   a dresser configured to dress the polishing surface of the polishing pad; and   a diagnostic device configured to monitor a thickness of the polishing pad and a polishing rate of the substrate,   wherein said diagnostic device is configured to diagnose a condition of the polishing surface of the polishing pad based on a change in the thickness of the polishing pad and on a change in the polishing rate.   
     
     
         40 . The polishing apparatus according to  claim 39 , wherein said diagnostic device is configured to determine an end of a life of the polishing pad based on a result of the diagnosis of the condition of the polishing surface. 
     
     
         41 . A polishing apparatus comprising:
 a polishing table for supporting a polishing pad;   a top ring having an air bag configured to press a substrate against a polishing surface of the polishing pad;   a dresser configured to dress the polishing surface of the polishing pad; and   a diagnostic device configured to monitor a flow rate of a gas supplied into the air bag,   wherein said diagnostic device is configured to diagnose a condition of the polishing surface of the polishing pad based on the flow rate of the gas.   
     
     
         42 . The polishing apparatus according to  claim 41 , wherein said diagnostic device is configured to determine an end of a life of the polishing pad based on a result of the diagnosis of the condition of the polishing surface. 
     
     
         43 . The polishing apparatus according to  claim 41 , wherein said diagnostic device is configured to measure a magnitude between peak and peak of a wave depicted by the flow rate during polishing of each one of a predetermined number of substrates, calculate an average of the magnitude measured for the predetermined number of substrates, and compare the average with a predetermined management value to diagnose the condition of the polishing surface. 
     
     
         44 . The polishing apparatus according to  claim 43 , wherein said diagnostic device is configured to determine that the polishing pad has reached the end of its life if the average has reached the management value. 
     
     
         45 . The polishing apparatus according to  claim 41 , wherein said diagnostic device is configured to perform a frequency analysis of the flow rate that fluctuates according to a rotation period of the polishing table, selectively monitor a power spectrum at the same frequency as that of the rotation period of the polishing table, and compare the power spectrum with a predetermined management value to diagnose the condition of the polishing surface.