MANUFACTURE OF SEMICONDUCTOR

PURPOSE:To divide a wafer into chips, by closely holding the wafer between metal plates having different coefficients of linear expansion, and heating the upper and lower metal plates so as to curve them. CONSTITUTION:The wafer 2 is closely held between the metal plates 5 and 6 and fixed by screws 7a-7b. When heating is performed under this state, the metal plate 5 is curved since the coefficient of linear expansion of the plate 5 is larger than that of the plate 6, and the wafer is cleft along cleavage grooves 2a. The chips can be recovered without contaminating the edges of the chips by removing the screws 7a-7d. The curvature of the curve can be changed by the value of the temperature rise. In this constitution, the chips can be obtained without contaminating the edges of the chips efficiently.