Selective dry etch of a dielectric film
AssigneeInternational Business Machines Corporation
InventorsDelores A. Bennett, James P. Norum, Hongwen Yan, Chienfan Yu
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Abstract
A process of etching an oxide layer placed over a nitride layer of a substrate with high selectivity. The process comprises plasma etching the oxide layer of the substrate with a carbon and fluorine-containing gas and with a nitrogen-containing gas. A SixNy species is formed which is deposited on the nitride layer substantially in equilibrium with etching of the nitride layer.
Claims18
A process for etching an oxide layer placed over a nitride layer in an upper portion of a substrate with high etching selectivity for the oxide layer, the process comprising:
- providing a plasma derived from a carbon and fluorine-containing gas and from a nitrogen-containing gas;
- and
- etching the substrate in the plasma in contact with the substrate,
- wherein the etching produces SiF4, the plasma contains SixNy species derived from a reaction of SiF4 and nitrogen species, and the SixNy species is deposited on the nitride layer substantially in equilibrium with the etching of the nitride layer.
An etch process selective to an oxide placed over a nitride, the process comprising the steps of:
- exposing to a fluorocarbon-nitrogen plasma a substrate having an oxide layer placed over a nitride layer;
- etching the oxide layer and the nitride layer to produce a SixNy species;
- and
- depositing the SixNy species on the nitride layer in substantial equilibrium with etching of the nitride layer.
Dependencies are inferred from the claim text.