Molecular‐beam epitaxial growth of high‐quality InSb on InP and GaAs substrates

Abstract

Epitaxial layers of InSb have been grown in InP and GaAs substrates by molecular‐beam epitaxy. The dependence of the epilayer quality on flux ratio, JSb4/JIn , was studied. Deviation from an optimum value of JSb4/JIn (∼2) during growth led to deterioration in the surface morphology and the electrical and crystalline qualities of the films. Room‐temperature electron mobilities as high as 70 000 and 53 000 cm2/V s were measured in InSb layers grown on InP and GaAs substrates, respectively. Unlike the previous results, the conductivity in these films is n type even at T=13 K, and no degradation of the electron mobility due to the high density of dislocations was observed. The measured electron mobilities (and carrier concentrations) at 77 K in InSb layers grown on InP and GaAs substrates are 110 000 cm2/V s (3×1015 cm−3) and 55 000 cm2/V s (4.95×1015 cm−3), respectively, suggesting their application to electronic devices at cryogenic temperatures.