Patent attributes
A grinding method for a wafer having a plurality of devices on the front side, wherein the back side of the wafer is ground by a grinding wheel to suppress the motion of heavy metal in the wafer by a gettering effect and also to maintain the die strength of each device at about 1,000 MPa or more. The grinding wheel is composed of a frame and an abrasive member fixed to the free end of the frame. The abrasive member is produced by fixing diamond abrasive grains having a grain size of less than or equal to 1 μm with a vitrified bond. A protective member is attached to the front side of the wafer and the wafer is held on a chuck table in the condition where the protective member is in contact with the chuck table. The grinding wheel is rotated as rotating the chuck table to thereby grind the back side of the wafer by means of the abrasive member so that the average surface roughness of the back side of the wafer becomes less than or equal to 0.003 μm and the thickness of a strain layer remaining on the back side of the wafer becomes 0.05 μm.
