Polishing method and polishing apparatus

Abstract

A polishing method capable of detecting a polishing endpoint where an upper layer is polished and a lower layer is exposed, without depending on changes in torque current and polishing rate is disclosed. The polishing method includes: supplying a polishing liquid onto a polishing pad on a polishing table while rotating the polishing table; polishing a workpiece in the presence of the polishing liquid by pressing the workpiece against the polishing pad; irradiating the workpiece with light each time the polishing table makes one rotation, and generating a spectrum of reflected light from the workpiece; calculating an index value indicating similarity between the spectrum of the reflected light and an interface spectrum; and determining a polishing endpoint at which the index value is maximized or minimized. The interface spectrum is a spectrum of reflected light from a reference workpiece generated when a first film is removed and a second film underlying the first film is exposed during polishing of the reference workpiece.

Dependencies are inferred from the claim text.