Wafer including a reinforcing flange formed upright at a periphery and method for manufacturing the same

Abstract

A wafer with an orientation notch being cut in a portion of its circumference, the wafer includes: a reinforcing flange formed upright at periphery; and a thin section surrounded by the reinforcing flange and having a smaller thickness than the reinforcing flange. The reinforcing flange includes a circumferential portion formed upright along the circumference and a notch portion formed upright near the orientation notch, and a width of the circumferential portion as viewed parallel to a major surface of the wafer is smaller than a depth of the orientation notch as viewed parallel to the major surface.

1 . A method for manufacturing a wafer, the wafer with an orientation notch being cut in a portion of its circumference, the wafer including:
 a reinforcing flange formed upright at periphery; and   a thin section surrounded by the reinforcing flange and having a smaller thickness than the reinforcing flange,   the reinforcing flange including a circumferential portion formed upright along the circumference and a notch portion formed upright near the orientation notch, and   the width of the circumferential portion as viewed parallel to a major surface of the wafer being smaller than the depth of the orientation notch as viewed parallel to the major surface, the method comprising:
 forming a mask at the periphery; and 
 forming the reinforcing flange by etching a portion not covered with the mask. 
   
     
     
         2 . The method according to  claim 1 , wherein a taper or a curved surface is formed on an upper end of an inner wall of the reinforcing flange. 
     
     
         3 . The method according to  claim 1 , wherein a taper or a curved surface is formed on a lower end of an inner wall of the reinforcing flange. 
     
     
         4 . The method according to  claim 2 , wherein a taper or a curved surface is formed on a lower end of the inner wall of the reinforcing flange. 
     
     
         5 . A wafer with an orientation flat formed by cutting out a portion of its circumference, the wafer comprising:
 a reinforcing flange formed upright at periphery; and   a thin section surrounded by the reinforcing flange and having a smaller thickness than the reinforcing flange,   as viewed parallel to a major surface of the wafer, a width of the reinforcing flange at the circumference being generally equal to a width of the reinforcing flange at the orientation flat.   
     
     
         6 . The wafer according to  claim 5 , wherein an upper end of an inner wall of the reinforcing flange adjacent to the thin section has a taper or a curved surface. 
     
     
         7 . The wafer according to  claim 5 , wherein a lower end of an inner wall of the reinforcing flange adjacent to the thin section has a taper or a curved surface. 
     
     
         8 . The wafer according to  claim 6 , wherein a lower end of the inner wall of the reinforcing flange adjacent to the thin section has a taper or a curved surface. 
     
     
         9 . A method for manufacturing a wafer, the wafer with an orientation flat formed by cutting out a portion of its circumference, the wafer including:
 a reinforcing flange formed upright at periphery; and   a thin section surrounded by the reinforcing flange and having a smaller thickness than the reinforcing flange,   as viewed parallel to a major surface of the wafer, a width of the reinforcing flange at the circumference being generally equal to a width of the reinforcing flange at the orientation flat, the method comprising:
 forming a mask at the periphery; and 
 etching a portion not covered with the mask. 
   
     
     
         10 . The method according to  claim 9 , wherein a taper or a curved surface is formed on an upper end of an inner wall of the reinforcing flange. 
     
     
         11 . The method according to  claim 9 , wherein a taper or a curved surface is formed on a lower end of an inner wall of the reinforcing flange. 
     
     
         12 . The method according to  claim 10 , wherein a taper or a curved surface is formed on a lower end of the inner wall of the reinforcing flange.