Mass-Spectrometry Investigation of the Kinetics of the Molecular-Beam Epitaxy of CdTe

The adsorption of Cd and Te on the surface of a CdTe crystal is studied in situ using a mass spectrometer in the temperature range of 500−700 K and at an incident flux intensity of VCd = 10–2−2 single layers per second, SL/s, and VTe = 0.5−5 SL/s. Computer programs for controlling the experiment and processing the obtained information are developed. The growth parameters are in good agreement with the proposed model of adsorption. The activation energies of the “evaporation” (transition of atoms from the crystal to the adsorption layer) and desorption of Cd atoms and Te2 molecules are 2 and 0.5 eV and 0.59 eV, respectively. It is established that the dependence of the growth rate on the Te2 flux at a constant Cd flux is linear over a wide range, while the dependence of the growth rate on the Cd flux at a constant Te2 flux is nonlinear and reaches saturation. The growth parameters depend on the structural features of the crystal surface (roughness, polycrystallinity, and mosaicity) accompanying film growth at large deviations from equilibrium.