Method of controlling plasma etch process

Abstract

A method for automated monitoring and controlling of a semiconductor wafer plasma etching process including collecting data versus time during a plasma etching process said data including information representative of a concentration of at least one pair of reactant and product species present during the course of the plasma etching process; calculating a selected ratio of at least one reactant species and one product species at selected time intervals in the plasma etching process to create real-time reactant-product ratio data; retrieving pre-determined reactant-product ratio data for the at least one reactant species and one product species for comparison with the real-time reactant-product ratio data; comparing the pre-determined reactant-product ratio data with the real-time reactant-product ratio data to determine a difference; and, adjusting at least one plasma process operating parameter to minimize the difference.

Dependencies are inferred from the claim text.