POST ETCH REACTIVE PLASMA MILLING TO SMOOTH THROUGH SUBSTRATE VIA SIDEWALLS AND OTHER DEEPLY ETCHED FEATURES

摘要

A method of smoothing the sidewalls of an etched feature using reactive plasma milling. The method of smoothing reduces the depth of sidewall notching, which causes the roughness on the feature wall surface. The method comprises removing residual polymeric materials from the interior and exterior surfaces of said silicon-comprising feature and treating the interior surface of the silicon-comprising feature with a reactive plasma generated from a source gas while the silicon-comprising feature is biased with a pulsed RF power. The source gas includes a reagent which reacts with the silicon and an inert gas. The method provides a depth of a notch on the interior surface of about 500 nm or less.