| 摘要 |
An object of the present invention is to provide a semiconductor wafer having a front and a back surfaces polished so as to have different glossiness from each other, yet with a lower cost. The glossiness of the front surface and the back surface can be selected arbitrarily. In a double-sided polisher with no sun gear, silicon wafers W are inserted in respective holding holes 11a of a carrier plate 11. The wafers W are placed with their back surfaces facing up. An expanded urethane foam pad 14 is pressed against the back surfaces of the wafers W and a non-woven fabric pad 15 is pressed against the front surfaces of the wafers W. A carrier holder 20 and thus the carrier plate 11 are then driven to make a circular motion associated with no rotation on their own axes within a horizontal plane while supplying a slurry to the wafers W from an upper surface plate 12 side. As a result, each of the front and the back surfaces of respective silicon wafers W can be polished uniformly over entire area thereof respectively. At that time, the urethane pad 14 has a sink rate of the wafer lower than that of the non-woven fabric pad 15. Therefore, such a polished wafer having the back surface formed into a satin-finished surface and the front surface formed into a mirror-finished surface can be obtained. Alternatively, those polishing cloths having different sink rates from each other may be employed for the upper and the lower surface plates, respectively. Further, the upper surface plate and the lower surface plate may be rotated at different speeds from each other. Those methods are also advantageously used to manufacture the semiconductor wafer having different glossiness between the front surface and the back surface thereof.
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