Structure-property relationships in heteroepitaxial InAs and InSb thin films

Heteroepitaxial thin films of InSb and InAs were evaporated onto sapphire and onto semi-insulating GaAs substrates. An in-line high vacuum evaporation set-up was used to deposit the semiconductor films by the three-temperature method at an ambient pressure of about 10^-5 mbar. The orientation and structure of the films were investigated as functions of substrate temperature and substrate orientation.The highest carrier mobilities were observed in (100)-oriented InAs and InSb films deposited on GaAs (100) substrates; these films had room temperature mobilities of 20 000 and 40 000 cm² V^-1 s^-1 respectively. InAs films on (0001) sapphire planes always showed (111) orientation with a maximum carrier mobility of 13 000 cm² V^-1 s^-1 at room temperature.