| 摘要 |
PURPOSE:To make the polishing rate in a wafer face constant and obtain a wafer with high flatness by making the surface condition of a wafer installing part a concentric, linear or nonlinear slope from the center of the installing part to the outer periphery. CONSTITUTION:A wafer 3 is fixed to a wafer installing part 1 whose surface condition is a concentric, liner or nonlinear slope from the center to the outer periphery, with a wax 4 and, as a wafer polishing plate 2 is pressed against a surface plate 5, the center part is pressed against the polishing cloth 6 harder than the outer periphery part, and the distribution of contact pressure is the largest at the center, gradually becoming smaller toward the outer periphery. Therefore, the polishing rate is the largest at the center gradually becoming lower toward the outer periphery. On the other hand, since the polishing cloth 6 has elasticity and as the wafer 3 is in a little inwardly recessed state, there is difference in the contacting condition and the polishing-liquid feeding condition between the center part and the periphery part and, in general, the polishing rate is larger on the periphery part. And, by combining these two phenomena, the polishing rate in the wafer 3 face can be made constant, obtaining a wafer 3 with high flatness.
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