Polishing endpoint detection method

摘要

Method and apparatus for detecting an accurate polishing endpoint of a substrate based on a change in polishing rate are provided. The method includes: applying a light to the surface of the substrate and receiving a reflected light from the substrate; obtaining a plurality of spectral profiles at predetermined time intervals, each spectral profile indicating reflection intensity at each wavelength of the reflected light; selecting at least one pair of spectral profiles, including a latest spectral profile, from the plurality of spectral profiles obtained; calculating a difference in the reflection intensity at a predetermined wavelength between the spectral profiles selected; determining an amount of change in the reflection intensity from the difference; and determining a polishing endpoint based on the amount of change.

主权项

1. A method of detecting a polishing endpoint of a substrate, comprising:
polishing a surface of the substrate having a film with a polishing pad; applying a light to the surface of the substrate and receiving a reflected light from the substrate; obtaining a plurality of spectral profiles at predetermined time intervals, each spectral profile indicating reflection intensity at each wavelength of the reflected light; selecting at least one pair of spectral profiles, including a latest spectral profile, from said plurality of spectral profiles obtained; calculating a difference in the reflection intensity at at least one predetermined wavelength between said spectral profiles selected; determining an amount of change in the reflection intensity from said difference; and determining a polishing endpoint based on said amount of change.