Partial etch memorization via flash addition

Abstract

Provided is a method of creating structure profiles on a substrate using faceting and passivation layers. A first plasma etch process performed generating a faceted sidewall and a desired inflection point; a second plasma etch process is performed using an oxygen, nitrogen, or combined oxygen and nitrogen plasma, generating a passivation layer; and a third plasma etch process using operating variables of an etch chemistry on the faceted sidewall and the passivation layer to induce differential etch rates to achieve a breakthrough on near-horizontal surfaces of the structure, wherein the third plasma etch used is configured to produce a target sidewall profile on the substrate down to the underlying stop layer. Selected two or more plasma etch variables are controlled in the performance of the first plasma etch process, the second plasma etch process, and/or the third plasma etch process in order to achieve target sidewall profile objectives.