Silicon single crystal wafer fabricating method and silicon single crystal wafer

Abstract

At the time of fabricating a silicon single crystal wafer from a nitrogen-doped silicon single crystal grown according to the Czochralski method, a silicon single crystal wafer covered with a region in which an oxygen precipitation bulk micro defect and an oxidation induced stacking fault mixedly exist is subjected to heat treatment at a temperature of 1100 to 1300° C. in a reducing gas or inert gas atmosphere. In such a manner, a method of fabricating a high-quality silicon single crystal wafer and a silicon single crystal wafer in which no grown-in crystal defects exist in the whole surface and oxygen precipitation bulk micro defects (BMD) are formed at a sufficiently high density to display the IG effect on the inner side can be provided. The single crystal wafer can be suitably used to form an operation region of a semiconductor device.

What is claimed is:  
     
         1 . A silicon single crystal wafer fabricating method of fabricating a silicon single crystal wafer from a nitrogen-doped silicon single crystal grown according to the Czochralski method, 
 wherein a silicon single crystal wafer covered with a region in which an oxygen precipitation bulk micro defect and an oxidation induced stacking fault mixedly exist is subjected to heat treatment at a temperature of 1100 to 1300° C. in a reducing gas or inert gas atmosphere.    
     
     
         2 . The silicon single crystal wafer fabricating method according to  claim 1 , wherein at the time of growing said nitrogen-doped silicon single crystal, a V/G value as a ratio between a pulling rate V (mm/min) of a single crystal and a temperature gradient G (° C./mm) in the axial direction of the single crystal where a region in which both the oxygen precipitation bulk micro defect and an oxidation induced stacking fault mixedly exist is formed, near a crystallization interface is preliminarily determined at each doping nitrogen concentration, and a pulling condition is adjusted so as to satisfy the V/G value, thereby forming a region in which an oxygen precipitation bulk micro defect and an oxidation induced stacking fault mixedly exist in the single crystal.  
     
     
         3 . A silicon single crystal wafer fabricated by the silicon single crystal wafer fabricating method according to  claim 1  or  2 , 
 wherein no grown-in crystal defects exist in a surface layer portion having a depth of at least 10 μm from the surface, and oxygen precipitation bulk micro defects are formed at a density of 1×10 9 /cm 3  or higher on the inner side.