Cmp apparatus, polishing pad and cmp method

Abstract

According to one embodiment, a CMP apparatus includes a supplying portion supplying a slurry to a surface portion of a polishing pad including water-soluble particles, a holding portion contacting an object to be polished with the surface portion of the polishing pad in a condition of holding the object, a temperature setting portion on the surface portion of the polishing pad, the temperature setting portion setting a temperature of the surface of the polishing pad. A control portion executes a first polishing step and a second polishing step after the first polishing step, the object is polished in a condition of setting the temperature of the surface of the polishing pad within a first temperature range in the first polishing step, and the object is polished in a condition of setting the temperature of the surface of the polishing pad within a second temperature range in the second polishing step.

1 . A CMP apparatus comprising:
 a supplying portion supplying a slurry to a surface portion of a polishing pad including water-soluble particles;   a holding portion contacting an object to be polished with the surface portion of the polishing pad in a condition of holding the object;   a temperature setting portion on the surface portion of the polishing pad, the temperature setting portion setting a temperature of the surface of the polishing pad; and   a control portion controlling an operation of the supplying portion, the holding portion and the temperature setting portion,   wherein the control portion executes a first polishing step and a second polishing step after the first polishing step, the object is polished in a condition of setting the temperature of the surface of the polishing pad within a first temperature range in the first polishing step, and the object is polished in a condition of setting the temperature of the surface of the polishing pad within a second temperature range in the second polishing step.   
     
     
         2 . The apparatus of  claim 1 , wherein the control portion controls an operation of the temperature setting portion based on a dissolved threshold value at which the water-soluble particles completely dissolve into the slurry. 
     
     
         3 . The apparatus of  claim 1 , wherein a solubility of the water-soluble particles exposed to the surface portion of the polishing pad in the second polishing step is higher than the solubility of the water-soluble particles exposed to the surface portion of the polishing pad in the first polishing step. 
     
     
         4 . The apparatus of  claim 3 , wherein the solubility of the water-soluble particles is controlled by causing the slurry supplied to the surface portion of the polishing pad from the supplying portion to contain a substance that is the same as the water-soluble particles or has the same property as the water-soluble particles in advance. 
     
     
         5 . The apparatus of  claim 1 , further comprising a stage portion on which the polishing pad is mounted,
 wherein the holding portion and the stage portion are driven to rotate, and   the control portion monitors a torque current value used to drive the holding portion or the stage portion to rotate and changes the first polishing step to the second polishing step after the torque current value is judged to have passed through a first change point.   
     
     
         6 . The apparatus of  claim 5 , further comprising a surface conditioning portion that conditions a state of the surface portion of the polishing pad,
 wherein the control portion terminates the second polishing step after the torque current value is judged to have passed through a second change point and executes a surface conditioning step for returning the surface portion of the polishing pad to an initial state by the surface conditioning portion after the temperature of the surface portion of the polishing pad is changed from within the second temperature range to within the first temperature range.   
     
     
         7 . The apparatus of  claim 1 , wherein the temperature setting portion includes a heat exchanger in contact with the surface portion of the polishing pad. 
     
     
         8 . The apparatus of  claim 1 , wherein the temperature setting portion includes a mechanism that supplies an inert gas to the surface portion of the polishing pad. 
     
     
         9 . The apparatus of  claim 1 , wherein the temperature setting portion includes a mechanism to cool the surface portion of the polishing pad and the temperature of the surface portion of the polishing pad is controlled by frictional heat between the polishing pad and the object to be polished and the mechanism. 
     
     
         10 . The apparatus of  claim 9 , wherein the temperature of the surface portion of the polishing pad changes linearly. 
     
     
         11 . The apparatus of  claim 1 , wherein the water-soluble particles are dextrin or cellulose containing an aliphatic chain. 
     
     
         12 . A polishing pad using the apparatus of  claim 1 , comprising:
 a water-insoluble crosslinked polymer; and   water-soluble particles in the crosslinked polymer,   wherein a solubility of the water-soluble particles changes during polishing of an object to be polished.   
     
     
         13 . A CMP method comprising:
 supplying slurry to a surface portion of a polishing pad including water-soluble particles;   bringing an object to be polished into contact with the surface portion of the polishing pad; and   executing a first polishing step and a second polishing step after the first polishing step, the object being polished in a condition of setting the temperature of the surface portion of the polishing pad within a first temperature range in the first polishing step, and the object being polished in a condition of setting the temperature of the surface portion of the polishing pad within a second temperature range in the second polishing step.   
     
     
         14 . The method of  claim 13 , wherein a solubility of the water-soluble particles exposed to the surface portion of the polishing pad in the second polishing step is higher than a solubility of the water-soluble particles exposed to the surface portion of the polishing pad in the first polishing step. 
     
     
         15 . The method of  claim 13 , wherein a solubility of the water-soluble particles is controlled by causing the slurry supplied to the surface portion of the polishing pad from the supplying portion to contain a substance that is the same as the water-soluble particles or has the same property as the water-soluble particles in advance. 
     
     
         16 . The method of  claim 13 , wherein the object to be polished and the polishing pad are driven to rotate, and
 a torque current value at which the object to be polished or the polishing pad is driven to rotate is monitored and the first polishing step is changed to the second polishing step after the torque current value is judged to have passed through a first change point.   
     
     
         17 . The method of  claim 16 , wherein polishing of the object to be polished is terminated after the torque current value is judged to have passed through a second change point, and
 the surface portion of the polishing pad is returned to an initial state after the temperature of the surface portion of the polishing pad is changed from within the second temperature range to within the first temperature range.   
     
     
         18 . The method of  claim 13 , wherein the temperature of the surface portion of the polishing pad is set by a heat exchanger in contact with the surface portion of the polishing pad. 
     
     
         19 . The method of  claim 13 , wherein the temperature of the surface portion of the polishing pad is set by a mechanism that supplies an inert gas to the surface portion of the polishing pad. 
     
     
         20 . The method of  claim 13 , wherein the temperature of the surface portion of the polishing pad is set by frictional heat between the polishing pad and the object to be polished and a mechanism to cool the surface portion of the polishing pad.