Grinding method

Abstract

A grinding method includes a holding step of holding a laminated wafer such that a wafer included in the laminated wafer is exposed, after the holding step, a first grinding step of grinding the wafer thicknesswise with respect to the wafer to remove part of a central region of the wafer and leave an outer circumferential region of the wafer that surrounds the central region unremoved, and after the first grinding step, a second grinding step of grinding the wafer thicknesswise with respect to the wafer to remove at least a portion of the outer circumferential region of the wafer. The load imposed on the laminated wafer in the second grinding step is smaller than the load imposed on the laminated wafer in the first grinding step.

What is claimed is: 
     
         1 . A grinding method of grinding a laminated wafer including a beveled wafer, comprising:
 a holding step of holding the laminated wafer such that the wafer is exposed;   after the holding step, a first grinding step of grinding the wafer thicknesswise with respect to the wafer to remove part of a central region of the wafer and leave an outer circumferential region of the wafer that surrounds the central region unremoved; and   after the first grinding step, a second grinding step of grinding the wafer thicknesswise with respect to the wafer to remove at least a portion of the outer circumferential region of the wafer,   wherein a load imposed on the laminated wafer in the second grinding step is smaller than the load imposed on the laminated wafer in the first grinding step.   
     
     
         2 . The grinding method according to  claim 1 , wherein the second grinding step includes grinding a surface of the outer circumferential region of the wafer to form thereon a step that includes a circular lower surface and an annular upper surface that extends around the circular lower surface. 
     
     
         3 . The grinding method according to  claim 1 , wherein the second grinding step includes grinding a surface of the outer circumferential region of the wafer to form an even upper surface entirely thereon. 
     
     
         4 . The grinding method according to  claim 1 , wherein the second grinding step includes grinding a surface of the outer circumferential region of the wafer to form thereon a step that includes a circular upper surface and an annular lower surface that extends around the circular upper surface. 
     
     
         5 . The grinding method according to  claim 1 , wherein the second grinding step comprises grinding a surface of the outer circumferential region of the wafer to eliminate the outer circumferential region of the wafer in its entirety. 
     
     
         6 . The grinding method according to  claim 5 , wherein the laminated wafer further includes an adhesive provided on a surface of the wafer that is opposite a ground surface, and
 the second grinding step is terminated when a value of a physical quantity that varies depending on the load imposed on the laminated wafer becomes equal to or higher than a predetermined threshold value.