Quantitative growth-investigation of zincblend ZnMgSe/GaAs(001) and ZnSe/GaAs(001) by means of RHEED, HRXRD and thickness monitoring

We report on reflection high energy electron diffraction (RHEED), high resolution X-ray diffraction (HRXRD) and thickness monitoring measurements of molecular beam epitaxy (MBE) grown ZnSe/GaAs (0 0 1) and Zn1-xMgxSe/GaAs (0 0 1) samples. We measured the particle flux rates with a thickness monitor prior to growth and used RHEED intensity oscillations during growth of ZnSe and Zn1-xMgxSe for calculating the number of incorporated atoms. Thereby we accurately determined the sticking coefficients of Zn and Mg dependent on the VI :II-flux ratio and growth temperature. We show the lattice relaxation of metastable zincblende MgSe/GaAs(0 0 1) by RHEED and determine for the first time the in-plane lattice constant of MgSe. The Mg content x in Zn1-xMgxSe/ZnSe/GaAs (0 0 1) (x < 0.37) is calculated from the relative difference in growth rates measured by RHEED. These results agreed very well with high resolution X-ray diffraction (HRXRD) measurements for growth under Se-rich conditions, whereas a strong disagreement was recognized under cation-rich conditions. (C) 1998 Elsevier Science B.V. All rights reserved.