Patent ID: 6358362
Filing Date: 2002-03-19
Classification: B24B,H01J,H01L

Abstract:
An arrangement for determining endpoints in an etching process within a plasma etching chamber, the arrangement comprising:a sensor configured to measure a first intensity of optical emissions having a first wavelength, and a second intensity of optical emissions having a second wavelength as emitted from within the plasma chamber during a first etching process and a subsequent second etching process of a semiconductor wafer; and a controller coupled to the sensor and configured to determine an endpoint for the first etching process based on a ratio signal generated from the first intensity and the second intensity, and stop the first etching process at the endpoint for the first etching process, and wherein the controller is further configured to start the second etching process after the endpoint for the first etching process, and the controller is further configured to determine an endpoint for the second etching process based on the ratio signal of the first intensity and the second intensity, and stop the second etching process at the endpoint for the second etching process.