Grinding method for grinding back-surface of semiconductor wafer and grinding apparatus for grinding back-surface of semiconductor wafer used in same

Abstract

A grinding method for grinding a back surface of a semiconductor wafer that performs infeed grinding of a back surface of a wafer laminated body, the method, during the grinding of the back surface of the wafer laminated body, having: measuring respectively a thickness of an outer peripheral portion and an inner peripheral portion of the wafer laminated body; calculating a thickness difference between the thickness of the outer portion and the thickness the inner portion; and tilting an axis of a grinding wheel by a predetermined angle in an arbitrary direction so as to reduce the calculated thickness difference.

1 . A grinding method for grinding a back surface of a semiconductor wafer,
 wherein a wafer laminated body having a support base material adhered to a front surface of said semiconductor wafer for protecting a circuit pattern formed on said front surface is fixed to a table with a front surface faced downward and with a back surface to be ground faced upward, and wherein, while said wafer laminated body is being rotated in a horizontal plane and a grinding wheel is being rotated about a axis of said grinding wheel, said grinding wheel is moved in a vertical direction at a predetermined feed speed to thereby grind said back surface of said wafer laminated body;   said method, during grinding of said back surface of said wafer laminated body, comprising:   measuring respectively a thickness of an outer peripheral portion and an inner peripheral portion of said wafer laminated body;   calculating a thickness difference between said thickness of said outer portion and said thickness of said inner portion; and,   tilting said axis of said grinding wheel so as to reduce the calculated thickness difference.   
     
     
         2 . A grinding method for grinding a back surface of a semiconductor wafer according to  claim 1 ,
 wherein said axis of said grinding wheel is tilted such that in-plane pressure distribution in the contact plane of said grinding wheel and said wafer laminated body becomes uniform.   
     
     
         3 . A grinding method for grinding a back surface of a semiconductor wafer according to  claim 1 ,
 wherein, when said thickness of said outer peripheral portion of said wafer laminated body is less than said thickness of said inner peripheral portion of said wafer laminated body, said axis of said grinding wheel is tilted such that said in-plane pressure in said outer peripheral portion of said wafer laminated body is comparable to or less than said in-plane pressure in said inner peripheral portion of said wafer laminated body.   
     
     
         4 . A grinding apparatus for grinding a back surface of a semiconductor wafer, comprising:
 a spindle head for supporting a grinding wheel having a grinding surface disposed in opposition to said back surface of a wafer laminated body rotatably about an axis of said grinding wheel;   a measurement means for measuring respectively a thickness of an outer peripheral portion and a thickness of an inner peripheral portion of said wafer laminated body;   an angle fine adjustment means for tilting said axis of said grinding wheel relative to a vertical direction; and,   a controller that receives input signal from said measurement means, calculates a thickness difference between said thickness of said outer peripheral portion and said thickness of said inner peripheral portion, and controls said angle fine adjustment means so as to reduce said thickness difference.