Etching of InAs in HCl Gas and Selective Removal of InAs Layer on GaAs in Ultrahigh-Vacuum Processing System

Abstract
The etch rate of InAs in HCl gas is studied for the first time and is found to be far greater than that of GaAs. The complete removal of an InAs layer grown on GaAs was achieved by this etching, resulting in a very flat surface. This is confirmed by the photoluminescence study on a novel GaAs/AlGaAs quantum well (QW), which was prepared by depositing a 50 nm InAs film at the center of the well, and subsequently etching it off before the remainder of the QW was formed. This unique selectivity can be employed to remove an InAs film which is used in the in situ patterning technique of GaAs.