Effect of substrate temperature on the growth rate and surface morphology of heteroepitaxial indium antimonide layers grown on (100) GaAs by metalorganic magnetron sputtering

Abstract

The effect of substrate temperature and III/V ratio on the growth rate and surface morphology of heteroepitaxial InSb films grown on GaAs(100) using metalorganic magnetron sputtering has been studied. The surface morphology showed a strong dependence on growth temperature and III/V ratio. Films with ‘‘mirrorlike’’ surfaces could be routinely obtained for deposition temperatures near 400 °C. For films grown above 300 °C, the growth rate increased with increasing trimethylindium flow, at constant antimony sputter power, and exhibited a peak near 400 °C. In this region the growth rate was thermally activated with an observed activation energy of 0.24 eV. Above 400 °C the growth rate decreased with increasing temperature. The surface morphology of these higher-temperature layers indicated a selective etching process as the mechanism for growth rate reduction. Cross-sectional transmission electron microscopy studies indicated a defect density in excess of 1011 cm−2 at the InSb/GaAs interface which decreased to 4.0×109 cm−2 at a distance of 0.3 μm from the interface.