Semiconductor wafer and method for fabrication thereof

Abstract

There is disclosed a semiconductor wafer obtained, at least, by removing a mechanical damage layer by etching both surfaces of the wafer, flattening one of the surfaces by a surface-grinding means, polishing both of the surfaces, and then subjecting a front surface of the wafer to a finishing mirror-polishing when defining the surface subjected to surface-grinding as a back surface of the wafer, and a method for fabricating it. There can be provided a method for fabricating a semiconductor wafer wherein grinding striations which remain on a semiconductor wafer even when double side polishing and finishing mirror-polishing are conducted after a conventional step of surface-grinding of the front surface or the both surfaces, are eliminated to improve quality of the front surface of the wafer, and the back surface having a quality suitable for the device process can be obtained, and a semiconductor wafer obtained thereby.

What is clained is:  
     
         1 . A semiconductor wafer obtained, at least, by removing a mechanical damage layer by etching both surfaces of the wafer, flattening one of the surfaces by a surface-grinding means, polishing both of the surfaces, and then subjecting a front surface of the wafer to a finishing mirror-polishing when defining the surface subjected to surface-grinding as a back surface of the wafer.  
     
     
         2 . A method for fabricating a semiconductor wafer comprising at least slicing a wafer from a semiconductor ingot, lapping both surfaces of the wafer, removing a mechanical damage layer by etching treatment, flattening one of the surfaces by a surface-grinding means, polishing both of the surfaces, and then subjecting a front surface of the wafer to a finishing mirror-polishing when defining the surface subjected to surface-grinding as a back surface of the wafer.  
     
     
         3 . The method for fabricating a semiconductor wafer according to  claim 2  wherein mirror edge polishing is conducted before or after polishing both of the surfaces.  
     
     
         4 . The method for fabricating a semiconductor wafer according to  claim 2  wherein the etching treatment is conducted by a wet etching method using an alkali solution as an etching solution.  
     
     
         5 . The method for fabricating a semiconductor wafer according to  claim 3  wherein the etching treatment is conducted by a wet etching method using an alkali solution as an etching solution.