Growth control of CdTe/CdZnTe (001) strained-layer superlattices by reflection high-energy electron diffraction oscillations
Résumé
We have used reflection high-energy electron diffraction (RHEED) and x-ray diffraction to study the growth of CdTe/Cd0.90 Zn0.10 Te (001) heterostructures by molecular beam epitaxy (MBE). A growth process involving an excess of Cd and growth interruptions at the well-barrier interfaces has been found necessary to observe strong and persistent RHEED oscillations during the epitaxy of quantum wells and superlattices. This method gives accurate in situ thickness measurements of all the layers during the growth of CdTe/Cd0.90 Zn0.10 Te superlattices, in good agreement with x-ray diffraction data. The sharpness of x-ray diffraction satellites confirms the high crystalline quality of the superlattices with a period fluctuation of less than one monolayer.