Atomic layer epitaxy of InP and InAs/InP heterostructures

The samples used for this study were InAs/InP strained single quantum wells and strained superlattices (SLS) grown by atomic layer epitaxy (ALE). The growth of InAs on InP is strongly influenced by the large lattice mismatch (3.22%). High resolution X-ray diffraction (HRXRD) was carried out. HRXRD can be used to quickly and precisely evaluate the ALE self-limiting growth rate of both InP and InAs. Using interference of X-ray wave fields in a ALE grown InP with an InAs marker layer the authors have accurately determined the growth per cycle. Raman spectra of AL grown InAs/InP SLSs show clearly the longitudinal acoustical folded modes and the longitudinal optic confined modes for both InAs and InP layers. The results indicate that despite the 3.2% lattice mismatch, ALE is a powerful method for fabricating highly strained InAs/InP structures with atomically controlled heterointerfaces