Patent ID: 9620377
Date: 2017-04-11
CPC Classifications: C23C,H01J,H01L

Claim:
1. A method of forming an etched feature in a dielectric-containing stack on a semiconductor substrate, the method comprising: (a) generating a first plasma comprising an etching reactant, exposing the substrate to the first plasma, and partially etching the feature in the dielectric-containing stack; (b) after (a), depositing a protective film on sidewalls of the feature, wherein the protective film comprises at least a first sub-layer and a second sub-layer, the first and second sub-layers being deposited under different conditions, the protective film comprising a metal, wherein the protective film is deposited along substantially the entire depth of the feature, and wherein the protective film comprises an electrically conductive film; and (c) repeating (a)-(b) until the feature is etched to a final depth, wherein the protective film deposited in (b) substantially prevents lateral etch of the feature during (a), and wherein the feature has an aspect ratio of about 5 or greater at its final depth.