PLASMA CONTROL USING DUAL CATHODE FREQUENCY MIXING

摘要

Methods for processing a substrate in a processing chamber using dual RF frequencies are provided herein. In some embodiments, a method of processing a substrate includes forming a plasma of a polymer forming chemistry to etch a feature into a substrate disposed on a substrate support in a process chamber while depositing a polymer on at least portions of the feature being etched. A low frequency and a high frequency RF signal are applied to an electrode disposed in the substrate support. The method further includes controlling the level of polymer formation on the substrate, wherein controlling the level of polymer formation comprises adjusting a power ratio of the high frequency to the low frequency RF signal.