Workpiece processing method

Abstract

A workpiece processing method includes: a first trimming step of cutting and removing the peripheral edge portion of the workpiece on the first wafer side while allowing a first cutting blade to cut into the peripheral edge portion; and a second trimming step of cutting and removing the peripheral edge while allowing a second cutting blade to cut into the peripheral edge portion from the first wafer side of the workpiece at a predetermined cut depth deeper than the cut depth of the first trimming step. The first trimming step includes rotating the first cutting blade in a rotation direction of cutting the workpiece from the second wafer side toward the first wafer side. The second trimming step includes rotating the second cutting blade in a rotation direction of cutting the workpiece from the first wafer side toward the second wafer side.

What is claimed is: 
     
         1 . A workpiece processing method of removing a peripheral edge portion on a first wafer side of a workpiece obtained by bonding a first wafer and a second wafer via a bonding layer, the workpiece processing method comprising:
 a holding step of holding the second wafer side of the workpiece on a holding surface of a holding table;   a first trimming step of cutting and removing the peripheral edge portion of the workpiece on the first wafer side while allowing a first cutting blade to cut into the peripheral edge portion of the workpiece held in the holding step; and   a second trimming step of, after the first trimming step, cutting and removing the peripheral edge while allowing a second cutting blade to cut into the peripheral edge portion from the first wafer side of the workpiece held in the holding step at a predetermined cut depth deeper than the cut depth of the first trimming step,   wherein the first trimming step includes rotating the first cutting blade in a rotation direction of cutting the workpiece from the second wafer side toward the first wafer side, and   the second trimming step includes rotating the second cutting blade in a rotation direction of cutting the workpiece from the first wafer side toward the second wafer side.   
     
     
         2 . The workpiece processing method according to  claim 1 , wherein the first cutting blade in the first trimming step does not cut into the second wafer. 
     
     
         3 . The workpiece processing method according to  claim 1 , wherein an abrasive of at least one of the first cutting blade and the second cutting blade has an abrasive diameter smaller than 30 μm.