Polishing method and polishing apparatus

Abstract

This invention provides a grinding method and apparatus capable of detecting the grinding endpoint of the upper layer being ground down to expose the lower layer, independent of changes in torque current and grinding rate. The grinding method involves supplying grinding fluid to a grinding pad (2) on the grinding table (3) while rotating the grinding table (3). The workpiece (W) is pressed against the grinding pad (2) to grind it in the presence of the grinding fluid. Light is irradiated onto the workpiece (W) every time the grinding table (3) rotates once, generating a spectrum of reflected light from the workpiece (W). An index value representing the similarity between the reflected light spectrum and the interface spectrum is calculated, and the index value is determined as the maximum or minimum grinding endpoint. The interface spectrum is the spectrum of reflected light from the reference workpiece generated when the first film is removed during the grinding of the reference workpiece, exposing the second film beneath the first film.

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