High aspect ratio etch with infinite selectivity
AssigneeLam Research Corporation
InventorsLeonid Belau, Eric A. Hudson
Life of this patent
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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.
Claims24
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.
An apparatus for processing a substrate, the apparatus comprising:
- a. a reaction chamber;
- b. a substrate support positioned within the reaction chamber;
- c. a plasma generator configured to generate a plasma within the reaction chamber;
- d. one or more inlets to the reaction chamber;
- and
- e. a controller having at least one processor, wherein the controller is configured to cause:
- i. positioning the substrate in the reaction chamber, the substrate comprising underlying material and a mask positioned above the underlying material, the underlying material comprising a dielectric material;
- ii. generating the plasma in the reaction chamber;
- and
- iii. exposing the substrate to the plasma in the reaction chamber to simultaneously (i) etch features in the underlying material on the substrate, 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.
Dependencies are inferred from the claim text.