US 9,039,908 B2 · Post etch reactive plasma milling to smooth through substrate via sidewalls and other deeply etched features

Abstract

A method of smoothing the sidewalls of an etched feature using reactive plasma milling. The method of smoothing reduces the depth of sidewall notching, which causes the roughness on the feature wall surface. The method comprises removing residual polymeric materials from the interior and exterior surfaces of said silicon-comprising feature and treating the interior surface of the silicon-comprising feature with a reactive plasma generated from a source gas while the silicon-comprising feature is biased with a pulsed RF power. The source gas includes a reagent which reacts with the silicon and an inert gas. The method provides a depth of a notch on the interior surface of about 500 nm or less.

Claims16

Dependent claims

A method of reactive plasma milling to smooth an interior surface of a silicon-comprising feature subsequent to etching of the feature, said method comprising:

removing residual polymeric materials from an interior surface of an etched silicon-comprising feature;
followed by
treating said interior surface of said etched silicon-comprising feature with a reactive plasma generated from a source gas which includes a reagent which reacts with silicon and an inert gas, while a substrate comprising said silicon-comprising feature is biased with a pulsed RF power, and wherein a pulsing frequency ranges from about 10 Hz to about 1000 Hz and a duty time % ranges from about 2% to about 40%, so that a milled interior surface of said etched silicon-comprising feature has a depth of notch of 700 nm or less.

Dependencies are inferred from the claim text.

Post etch reactive plasma milling to smooth through substrate via sidewalls and other deeply etched features

Life of this patent

Post etch reactive plasma milling to smooth through substrate via sidewalls and other deeply etched features

Life of this patent

Abstract

Claims16