XPS investigation of InAs etching in planar inductively coupled plasma

Abstract

A method of deep etching of InAs involving ICP plasma and hydrocarbon based chemistry is proposed. Optimal conditions and the composition of the gas phase for plasmachemical etching ensuring acceptable etch rates and providing the conservation of the surface relief were revealed. The effect of the CH4/H2/Ar RF (13.56 MHz) and ICP plasma on the InAs (111)A surface composition was investigated using XPS. It was shown that plasma etching leads to arsenic depletion of the surface up to ∼18 %. Consequent chemical etching in isopropanol saturated with hydrochloric acid and vacuum annealing at 300°C restore the initial surface stoichiometry.