Channeling studies of III–V/III–V and IV/III–V semiconductor modulated structures

Abstract

He+‐ion channeling spectrometry has been used to study the lattice crystallinity and interface structures of two different types of semiconductor superlattices: InAs–GaSb and Ge–GaAs, both (100)‐oriented and grown by molecular beam epitaxy (MBE). The channeling measurements indicate good epitaxy, low density of defects, and very interesting interface structures for these superlattices. Contrary to the bulk zinc blende and diamond crystals where the dechanneling yield along the 〈110〉 axis is lower than the 〈100〉 one, the InAs–GaSb superlattices invariably show much higher 〈110〉 dechanneling yields than those along the [100] growth direction over a wide range of thickness for the individual layers. The Ge–GaAs superlattices, on the other hand, show very low dechanneling yields along both the [100] growth direction and 〈110〉 axis for the thicker layer structures; the dechanneling yields along the [100] axis, however, increase rapidly for the thinner‐layer structures with little change of the 〈110〉 ones. Thes...