High aspect ratio etch with infinite selectivity
AssigneeLam Research Corporation
InventorsLeonid Belau, Eric A. Hudson
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Abstract
Provided herein are methods and apparatus for processing a substrate by exposing the substrate to plasma to simultaneously (i) etch features in an underlying material (e.g., which includes one or more dielectric materials), and (ii) deposit a upper mask protector layer on a mask positioned over the dielectric material, where the upper mask protector layer forms on top of the mask in a selective vertically-oriented directional deposition. Such methods and apparatus may be used to achieve infinite etch selectivity, even when etching high aspect ratio features.
Claims15
A method for processing a substrate, the substrate comprising underlying material and a mask, wherein the underlying material comprises at least one layer of silicon oxide, and wherein the mask is positioned above the underlying material and is patterned to define locations where features will be etched in the underlying material, the method comprising:
- a. generating a plasma in a reaction chamber;
- and
- b. exposing the substrate to the plasma in the reaction chamber to simultaneously
- (i) etch the features in the underlying material, and
- (ii) deposit an upper mask protector layer on the mask, wherein the upper mask protector layer forms on top of the mask in a selective vertically-oriented directional deposition,
- wherein the upper mask protector layer comprises a CxBryFz-based material, a CxClyFz-based material, a CxIyFz-based material, or a combination thereof.
Dependencies are inferred from the claim text.