Etch process for reducing silicon recess
First Claim
1. A method for selectively etching a substrate, comprising:
- disposing a substrate comprising a silicon nitride (SiNy) layer overlying silicon in a plasma etching system;
transferring a pattern to said silicon nitride layer using a plasma etch process, wherein said plasma etch process utilizes a process gas composition having as incipient ingredients a process gas containing C, H and F, and an additive gas including CO2; and
selecting an amount of said additive gas in said plasma etch process to achieve;
(1) a silicon recess formed in said silicon having a depth less than 10 nanometers (nm), and (2) a sidewall profile in said pattern having an angular deviation from 90 degrees less than 2 degrees.
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Abstract
A method for selectively etching a substrate is described. The method includes disposing a substrate comprising a silicon nitride (SiNy) layer overlying silicon in a plasma etching system, and transferring a pattern to the silicon nitride layer using a plasma etch process, wherein the plasma etch process utilizes a process composition having as incipient ingredients a process gas containing C, H and F, and an additive gas including CO2. The method further includes: selecting an amount of the additive gas in the plasma etch process to achieve: (1) a silicon recess formed in the silicon having a depth less than 10 nanometers (nm), and (2) a sidewall profile in the pattern having an angular deviation from 90 degrees less than 2 degrees.
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Citations
20 Claims
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1. A method for selectively etching a substrate, comprising:
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disposing a substrate comprising a silicon nitride (SiNy) layer overlying silicon in a plasma etching system; transferring a pattern to said silicon nitride layer using a plasma etch process, wherein said plasma etch process utilizes a process gas composition having as incipient ingredients a process gas containing C, H and F, and an additive gas including CO2; and selecting an amount of said additive gas in said plasma etch process to achieve;
(1) a silicon recess formed in said silicon having a depth less than 10 nanometers (nm), and (2) a sidewall profile in said pattern having an angular deviation from 90 degrees less than 2 degrees. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification