Patent ID: 9711359
Date: 2017-07-18
CPC Classifications: H01L

Claim:
1. A method for etching a silicon or metal based etch layer in a stack over a substrate wherein the etch layer is under a carbon based mask layer which is under a patterned organic mask, comprising: placing the stack and substrate on a support in the plasma chamber; in situ depositing a silicon based layer over the stack, wherein the silicon based layer is a silicon oxide or silicon nitride based layer; etching the silicon based layer to form silicon based sidewalls or spacers on sides of the patterned organic mask; selectively etching the carbon based mask layer with respect to the silicon based sidewalls or spacers and the silicon or metal based etch layer, wherein the selectively etching the carbon based mask layer undercuts the silicon based sidewalls or spacers, comprising; selectively etching the silicon or metal based etch layer with respect to the carbon based mask layer and simultaneously removing the silicon based sidewalls; and removing the stack and substrate from the support and the plasma chamber.