Method of etching a substrate

摘要

This invention relates to a method of etching a substrate in a chamber on an electrostatic chuck, which defines a gas cooling path at the substrate/chuck interface. The method includes electrostatically clamping the substrate on the chuck with gas in the gas path being at a first pressure; etching the substrate at a first power; detecting the end point for the etc; reducing the gas pressure to a second pressure at which the substrate floats on a gas; and over etching the wafer at a second power, which is lower than the first power.