Wafer grinding method
AssigneeDisco Corporation
InventorsShinji Yoshida, Osamu Nagai
Life of this patent
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Abstract
A wafer grinding method is disclosed, in which only a region, corresponding to a device formation region, of the back side of a wafer is ground in rough grinding conducted first, while the part surrounding the region thus ground is left unground as an annular projected part, to prevent the outer peripheral edge of the wafer from becoming knife edge-like in shape. In the subsequent finish grinding, the annular projected part is ground and, further, the whole area of the back side of the wafer is ground to be flat. Chippings of the outer peripheral edge may be generated only during the finish grinding, whereby the chippings are prevented from occurring or limited to minute ones.
Claims2
A method of grinding a wafer having a device formation region provided with a plurality of devices on the front side thereof, said method comprising:
- a first grinding step of holding said wafer on a rotatable chuck table with its back side exposed, and grinding a region, corresponding to said device formation region, of said back side by a rotating type first grindstone or grindstones being annular in shape or arranged in an annular pattern so as to form a recess on said back side of said wafer and to form an annular projected part projected to the back side in the periphery of said device formation region;
- and
- a second grinding step of grinding the whole area of said back side of said wafer inclusive of said annular projected part by a rotating type second grindstone or grindstones being smaller in abrasive grain diameter than said first grindstone or grindstones being annular in shape or arranged in an annular pattern so as to flatten said back side.
Dependencies are inferred from the claim text.