Heteroepitaxial growth of InSb directly on (001) GaAs without any buffer layer using growth rate ramping by MBE

摘要

Heteroepitaxial InSb layers were grown on semi-insulating (001) GaAs substrates without any buffer layer showing good quality and acceptable electron mobilities at both 77K and 300K. The heteroepitaxial growth was started with the lowest possible rate by slowly ramping of Indium source temperature from its idle value up to the nominal one corresponding to a growth rate of approximately a micron per hour. This procedure speeds up the production and eliminates unwanted impurities without losing much mobility as a tradeoff. Also some empirical lines fitted to previously reported data indicating that creditable 77K (300K) mobilities of heteroepitaxial InSb/GaAs layers are within 30%–80% (50%–100%) of minimum homoepitaxial mobilities, and half of our measured mobilities are well within the regions.