Patent ID: 7063765

Claim:
A method for processing a wafer by using an adhesive sheet including (i) a first substrate, (ii) a first adhesive layer arranged on the first substrate, (iii) a second substrate arranged on the first adhesive layer, and (iv) a second adhesive layer arranged on the second substrate, wherein a chemical reaction which causes reduction in the adhesion of the first adhesive layer and a chemical reaction which causes reduction in the adhesion of the second adhesive layer are different, the method comprising: a first step of affixing the adhesive sheet to the wafer such that the second adhesive layer is disposed between the wafer and the second substrate; a second step of dicing the wafer into a plurality of chips, wherein the wafer is diced with the adhesive sheet affixed thereto, such that the second adhesive layer and the second substrate are diced together with the wafer without dicing the first substrate; a third step of peeling the first adhesive layer and the first substrate from the diced wafer by reducing adhesion of the first adhesive layer and, thereby, disjoining the plurality of chips from one another, wherein each of the disjoined plurality of chips has a portion of the second substrate affixed thereto by a portion of the second adhesive layer; and a fourth step of peeling the portion of the second adhesive layer and the portion of the second substrate from each of the plurality of chips by reducing the adhesion of the portion of the second adhesive layer.