Method for producing wafer notches with rounded corners and a tool therefor

Abstract

A semiconductor wafer for use in the fabrication of semiconductor devices which includes a circular wafer ( 13 ) of semiconductor material having a perimeter and a notch ( 11 ) having a wall disposed in the wafer and extending to the perimeter which includes a preferably rounded apex ( 5 ) interior of the perimeter and a pair of rounded intersections ( 7, 9 ) between the wall and the perimeter. The notch is formed with a tool ( 23 ) for forming rounded corners in the semiconductor wafer which includes a body of a material having a hardness greater than the semiconductor wafer which has a generally rounded or paraboloidally shaped front portion having a forwardmost tip ( 25 ) portion and a wing portion ( 27 ) extending outwardly from the body and having a taper narrowing in the direction of the forwardmost tip portion. The wing portion can be one or more spaced apart wing members or the wing portion can be a single member which extends completely around the tool axis. The notch is formed by rotating the tool and moving the tool in a direction along a radius of the wafer until the wing portion contacts the wafer and forms a rounded intersection between the notch and the wafer perimeter in the shape of the intersection of the rounded tip portion and the wing of the tool.

1 . A semiconductor wafer for use in the fabrication of semiconductor devices which comprises: 
 (a) a circular wafer of semiconductor material having a perimeter; and    (b) a notch having a wall disposed in said wafer and extending to said perimeter, said notch including: 
 (i) an apex interior of said perimeter; and  
 (ii) a pair of rounded intersections between said wall and said perimeter.  
   
     
     
         2 . The wafer of  claim 1  wherein said apex is rounded.  
     
     
         3 . A tool for forming rounded corners in a semiconductor wafer for use in the fabrication of semiconductor devices, which comprises: 
 (a) a body of a material having a hardness greater than said semiconductor wafer, said body having: 
 (i) a generally rounded front portion having a forwardmost tip portion; and  
 (ii) a wing portion extending outwardly from said body and having a taper narrowing in the direction of said forwardmost tip portion.  
   
     
     
         4 . The tool of  claim 3  wherein said body is formed of a material taken from the class consisting of silicon carbide and diamond.  
     
     
         5 . The tool of  claim 3  wherein said rounded front portion is in the shape of a paraboloid.  
     
     
         6 . The tool of  claim 4  wherein said rounded front portion is in the shape of a paraboloid.  
     
     
         7 . The tool of  claim 3  wherein said wing portion includes a plurality of spaced apart wing members.  
     
     
         8 . The tool of  claim 4  wherein said wing portion includes a plurality of spaced apart wing members.  
     
     
         9 . The tool of  claim 5  wherein said wing portion includes a plurality of spaced apart wing members.  
     
     
         10 . The tool of  claim 6  wherein said wing portion includes a plurality of spaced apart wing members.  
     
     
         11 . The tool of  claim 3  wherein said body has a major axis and said wing portion extends completely around said axis.  
     
     
         12 . The tool of  claim 4  wherein said body has a major axis and said wing portion extends completely around said axis.  
     
     
         13 . The tool of  claim 5  wherein said body has a major axis and said wing portion extends completely around said axis.  
     
     
         14 . The tool of  claim 6  wherein said body has a major axis and said wing portion extends completely around said axis.  
     
     
         15 . A method of providing a semiconductor wafer for use in the fabrication of semiconductor devices, which comprises the steps of: 
 (a) providing a tool having body of a material having a hardness greater than said semiconductor wafer, said body having: 
 (i) a generally rounded front portion having a forwardmost tip portion; and  
 (ii) a wing portion extending outwardly from said body and having a taper narrowing in the direction of said forwardmost tip portion;  
   (b) providing a circular semiconductor wafer having a perimeter; and    (c) forming a notch in said perimeter of said semiconductor wafer with said tool.    
     
     
         16 . The method of  claim 15  wherein said rounded front portion is in the shape of a paraboloid.  
     
     
         17 . The method of  claim 15  wherein said wing portion includes a plurality of spaced apart wing members.  
     
     
         18 . The method of  claim 16  wherein said wing portion includes a plurality of spaced apart wing members.  
     
     
         19 . The method of  claim 15  wherein said body has a major axis and said wing portion extends completely around said axis.  
     
     
         20 . The method of  claim 16  wherein said body has a major axis and said wing portion extends completely around said axis.