Methods for dry etching semiconductor devices

摘要

The present invention provides methods for etching semiconductor devices, such aluminum nitride resonators. The methods herein allow for devices having improved etch profiles, such that nearly vertical sidewalls can be obtained. In some examples, the method employs a dry etch step with a primary etchant gas that omits BCl3, a common additive.

主权项

1. A method for etching a semiconductor, the method comprising:
placing a patterned semiconductor into a plasma reactor, wherein the patterned semiconductor comprises a semiconductor material and a hard mask disposed directly or indirectly on a planar surface of the semiconductor material, and wherein the hard mask defines at least one trench pattern; introducing a first supplementary gas into the plasma reactor for a first supplemental period, wherein the first supplementary gas comprises BCl3 and wherein a duration of the first supplemental period is less than a duration of a primary etching period; etching an exposed semiconductor material located in proximity to the trench pattern by introducing a primary etchant gas into the plasma reactor for the primary etching period, wherein the primary etchant gas comprises Cl2 and does not include BCl3, thereby providing an etched semiconductor; and introducing a second supplementary gas into the plasma reactor for a second supplemental period, wherein the second supplementary gas comprises BCl3 and wherein a duration of the second supplemental period is less than a duration of the primary etching period.