Room temperature inductively coupled plasma etching of InAs/InSb in BCl_3/Cl_2/Ar

摘要

Inductively coupled plasma (ICP) etching of InAs and InSb at room temperature has been investigated using BCl_3/Cl_2/Ar plasma. Specifically, the etch rate and post-etching surface morphology were investigated as functions of the gas composition, ICP power, process pressure, and RF chuck power. An optimized process has been developed, yielding anisotropic etching and very smooth surfaces with roughnesses of 0.25 nm for InAs, and 0.57 nm for InSb, which is comparable with the surface of epi-ready polished wafers. The process provides moderate etching rates of 820 A/min for InAs and 2800 A/min for InSb, and the micro-masking effect is largely avoided.