POLISHING PAD SURFACE SHAPE MEASURING INSTRUMENT, METHOD OF USING POLISHING PAD SURFACE SHAPE MEASURING INSTRUMENT, METHOD OF MEASURING APEX ANGLE OF CONE OF POLISHING PAD, METHOD OF MEASURING DEPTH OF GROOVE OF POLISHING PAD, CMP POLISHER, AND METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

A main sensor (15) measures the distance Lm to the surface of a pad (2a), and a sub-sensor (16) measures the distance Ls to the surface of a reference block (12). The actually used measurement is the value (Lm+Ls). The reference block (12) is used to give a reference position for measuring the position of the surface of the pad (2a). Therefore, even if the position a mover (9) is varied by deformation of, e.g., a guide holding plate (7) or a guide (8), accurate measurement can be carried out. When a motor (11) is rotated, a ball screw (10) rotates, and the mover (9) moves to and fro so as to measure the distance to the pad (2a). From the distance measurement data, the cone apex angle, groove depth, thickness and so forth of the pad (2a) are determined.