Gas additives for sidewall passivation during high aspect ratio cryogenic etch

摘要: Methods and apparatus for etching a feature in substrate are provided. The may be etched dielectric material, which or not provided stack of materials. using cryogenic temperatures particular classes reactants. In various examples, the at temperature about −20° C. lower, mixture reactants that includes least one reactant is an iodine-containing fluorocarbon, fluoride, bromine-containing sulfur-containing reactant, another select set embodiments, combination low processing with results very effective bow control.