Molecular beam epitaxy growth of InSb films on GaAs

Abstract

InSb films have been grown by molecular beam epitaxy on GaAs substrates. The procedure incorporated a low-temperature (300°C) growth of a thin (300 Å) InSb interface layer prior to the InSb active layer growth at 380°C. A beam equivalent pressure ratio of Sb4 to In of 4 led to samples with the highest 77 K Hall mobilities. Hall mobilities in excess of 35 000 cm2 /V s at 77 K and x-ray rocking curve widths less than 250 arcsec are routinely achieved in films 2-5 μm thick. The 77 K Hall electron mobilities are a factor of 4 greater than recently reported results. The x-ray rocking curve widths are also substantially less. Possible explanations for the improved film properties are discussed.