Selectivity for etching an oxide over a nitride
AssigneeApplied Materials, Inc.
InventorsJeffrey Marks, Kenneth S. Collins, Chan-Lon Yang, David W. Groechel, Peter R. Keswick
Life of this patent
Estimating the term…
Abstract
A method of etching an oxide over a nitride with high selectivity comprising plasma etching the oxide with a carbon and fluorine-containing etchant gas in the presence of a scavenger for fluorine, thereby forming a carbon-rich polymer which passivates the nitride. This polymer is inert to the plasma etch gases and thus provides high selectivity to the etch process.
Claims22
A process for etching an oxide layer over a nitride layer in an upper portion of a substrate with high etching selectivity for said oxide, comprising etching said substrate in a plasma derived from a carbon- and fluorine-containing gas and contacted to a scavenger for fluorine aside from said substrate and from said carbon- and fluorine-containing gas and comprising a constituent selected from the group consisting of silicon and carbon.
An etch process selective to an oxide over a nitride, comprising the steps of:
- exposing to a fluorocarbon plasma a substrate comprising an oxide layer over a nitride layer to thereby etch said oxide layer;
- and
- contacting said fluorocarbon plasma to a solid source of silicon overlying said substrate.
Dependencies are inferred from the claim text.