摘要 |
Plasma etching of boron-doped carbonaceous mask layers with an etchant gas mixture including CxFy or CxHyFz, and at least one of COS and CF3I. Etchant gas mixtures may further include a carbon-free fluorine source gas, such as SF6 or NF3, and/or an oxidizer, such as O2, for higher etch rates. Nitrogen-containing source gases may also be provided in the etchant gas mixture to reduce sidewall bowing in high aspect ratio (HAR) feature etches.
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