Polishing method, polishing apparatus and polishing tool

Abstract

A polishing method and a polishing apparatus finish a surface of a substrate of a compound semiconductor containing an element such as Ga or the like to a desired level of flatness, so that the surface can be flattened with high surface accuracy within a practical processing time. In the presence of water, such as weak acid water, water with air dissolved therein, or electrolytic ion water, the surface of the substrate made of a compound semiconductor containing either one of Ga, Al, and In and a surface of a polishing pad having an electrically conductive member in an area of the surface which is held in contact with the substrate) are relatively moved while being held in contact with each other, thereby polishing the surface of the substrate.

1 - 52 . (canceled) 
     
     
         53 . A polishing tool comprising:
 an elastic base made of at least one of elastic materials including rubber, resin, foamable resin, and non-woven fabric;   an electrically conductive member disposed on the elastic base in an area held in contact with at least the substrate; and   an intermediate film interposed between the elastic base and the electrically conductive member for increasing adhesion therebetween.   
     
     
         54 . The polishing tool according to  claim 53 , wherein the intermediate film is made of carbon or chromium. 
     
     
         55 . The polishing tool according to  claim 53 , wherein the elastic base has grooves defined in a surface thereof for efficiently supplying the processing liquid. 
     
     
         56 . The polishing tool according to  claim 53 , wherein the elastic base has a number of through-holes for passing at least one of light and an ion current therethrough. 
     
     
         57 . A polishing apparatus comprising:
 a container for holding a processing liquid therein;   the polishing tool recited in  claim 53 , the polishing tool being disposed in the container while being immersed in the processing liquid;   a substrate holder for holding the substrate and bringing the substrate into contact with the polishing tool while immersing the substrate in the processing liquid in the container; and   a moving mechanism for relatively moving the polishing tool and the substrate held by the substrate holder while the polishing tool and the substrate are in contact with each other.   
     
     
         58 . The polishing apparatus according to  claim 57 , wherein the processing liquid comprises a pH buffer solution of a neutral pH which contains Ga ions, and the substrate is made of a semiconductor containing an element of Ga. 
     
     
         59 . A polishing apparatus comprising:
 the polishing tool recited in  claim 53 ;   a substrate holder for holding a substrate and bringing the substrate into contact with the polishing tool;   a moving mechanism for relatively moving the polishing tool and the substrate held by the substrate holder while the polishing tool and the substrate are in contact with each other; and   a processing liquid supply section for supplying a processing liquid to a contacting region of the polishing tool and the substrate held by the substrate holder.   
     
     
         60 . The polishing apparatus according to  claim 59 , wherein the processing liquid comprises a pH buffer solution of a neutral pH which contains Ga ions, and the substrate is made of a semiconductor containing an element of Ga.