Plasma etch processes for boron-doped carbonaceous mask layers

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