Methods of removing residual polymers formed during a boron-doped amorphous carbon layer etch process

摘要

Methods for removing residual polymers formed during etching of a boron-doped amorphous carbon layer are provided herein. In some embodiments, a method of etching a feature in a substrate includes: exposing a boron doped amorphous carbon layer disposed on the substrate to a first plasma through a patterned mask layer to etch a feature into the boron doped amorphous carbon layer, wherein the first plasma is formed from a first process gas that reacts with the boron doped amorphous carbon layer to form residual polymers proximate a bottom of the feature; and exposing the residual polymers to a second plasma through the patterned mask layer to etch the residual polymers proximate the bottom of the feature, wherein the second plasma is formed from a second process gas comprising nitrogen (N₂), oxygen (O₂), hydrogen (H₂), and methane (CH₄).