PRESSURE CONTROL DEVICE ON POLISHING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a pressure control device capable of realizing high flatness and favorable surface roughness by uniformly stabilizing surface pressure of a semiconductor wafer W.

SOLUTION: A liquid bearing layer is formed between a wafer holding surface Cw of a chuck 13 and the wafer W by supplying water to the wafer holding surface Cw of the chuck 13 as water is supplied to a supply passage 21 and a supply passage 17. A pressure control valve 30 (decompression valve 30) is set on an upstream point of a water bearing layer in the supply passage 21, and a controller 40 outputs a pressure command signal to the pressure control valve 30. Back press pressure Pw in the water bearing layer is controlled as pressure Pv of water at a pressure control valve setting point 30A of the supply passage 21 is regulated in accordance with the pressure command signal.

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