Plasma etching method, and production method for semiconductor element

Abstract

Disclosed is a plasma etching method for a substrate that enables formation of various forward-tapered shapes. The plasma etching method disclosed includes the steps of: (i) placing, in a chamber, a substrate 10 including a compound semiconductor layer 11 formed of a Group III-V compound semiconductor, and a resist mask 12 disposed on one principal surface 11a of the compound semiconductor layer 11; and (ii) plasma etching the compound semiconductor layer 11 and the resist mask 12 by exposing the compound semiconductor layer 11 and the resist mask 12 to a plasma, thereby forming a slope 11s that forms a forward-tapered shape on the compound semiconductor layer 11. The Group III-V compound semiconductor includes Ga and As. The plasma etching in the step (ii) is performed using, as an etching gas, a gas mixture including nitrogen gas and a gas containing chlorine.

Dependencies are inferred from the claim text.