Growth of (Zn)CdSe quantum structures on vicinal GaAs(001) substrates: step flow growth versus strain effects

Single ZnCdSe quantum wells (QWs) as well as stacks of CdSe sub-monolayer ( SML) insertions embedded in ZnSe have been grown on GaAs(001) substrates mi soriented up to 10 degrees towards the (111)A or the (011) direction, respe ctively. The influence of the substrate misorientation on the structural an d optical properties has been studied by high-resolution X-ray diffraction (HRXRD) and photoluminescence spectroscopy. HRXRD measurements revealed a s train-induced tilting of the II-VI layers with respect to the GaAs substrat e in excellent agreement with theoretical predictions. A decreased Cd incor poration with increasing misorientation angle was found for the ZnCdSe QWs due to the competition process between Zn and Cd. In case of the CdSe SMLs, the additional strain perpendicular to the surface overcompensates the adv antage of more binding partners at the step edges for Cd atoms leading to a possible formation of quantum structures only for the highest step density . (C) 2000 Elsevier Science B.V. All rights reserved.