Characterization of molecular beam epitaxially grown InSb layers and diode structures

Abstract InSb epitaxial layers have been grown on GaAs and InSb substrates by molecular beam epitaxy (MBE). A 14 μm-thick InSb film grown on a GaAs substrate with a 300 A buffer layer of InSb grown by atomic layer epitaxy has 65,000 and 125,000 cm 2 /Vs electron mobilities at room temperature and 77 K, respectively, and a 41 arcsec full width at half maximum (FWHM) X-ray rocking curve. The mobility was 60,000 and 110,000 cm 2 /Vs at room temperature and 77 K, respectively, for thicknesses of 4–5 μm when the sample was sequentially stripped. InSb diode structures were grown on GaAs substrates and processed to make mesa diodes. They had large leakage currents and zero bias resistance area products ( R 0 A ) were less than 100 Σ-cm 2 at 77 K. However a homoepitaxially grown InSb diode had a R 0 A value of 2.5 × 10 5 Ω-cm 2 at 77 K. The leakage current density was 7.0 × 10 −8 A/cm 2 at 25 mV reverse bias. This is the first reported high performance InSb diode grown by MBE.