Controlled p- and n-type doping of homo- and heteroepitaxially grown InSb

Abstract

The p- and n-type doping, with Be and Si, respectively, of InSb grown on InSb and GaAs substrates using molecular-beam epitaxy was investigated. Using secondary-ion-mass spectrometry, an anomalous migration of Be toward the surface was observed for growth on InSb substrates when the substrate temperature exceeded 340 °C. This migration was not observed for Be-doped InSb layers grown on GaAs substrates. This redistribution of dopants was also not observed for Si-doped InSb layers. The doping efficiency of Be in InSb was approximately one-half that measured for Be in GaAs. For the doping efficiency of Si in InSb to reach that for Si in GaAs, the substrate temperature had to be maintained at ≤340 °C during growth. Using the low-temperature growth technique, Si delta-doped structures were grown which demonstrated two-dimensional electron gas behavior.