ATOMIC LAYER EPITAXY OF CDTE-ZNTE AND CDTE-MNTE SUPERLATTICES

CdTe-ZnTe superlattices (SLs) with a period ranging from 13 to 38 angstrom have been grown by atomic layer epitaxy (ALE) on (001) GaAs-substrates. In a substrate temperature range between 270 and 290-degrees-C, the growth rate for both CdTe and ZnTe regulated itself to exactly 0.5 monolayers per reaction cycle, allowing the growth of very precisely tailored structures. For lower substrate temperatures, the growth rate raised to approximately 0.8 monolayers per cycle, but did not reach one monolayer per cycle before ZnTe started to grow polycrystalline. Using the ALE growth parameters for CdTe, SLs of CdTe and metastable cubic MnTe were prepared. The superlattices were characterized by high resolution x-ray diffraction and photoluminescence. A comparision of x-ray data and computer simulations, based on the dynamical theory of x-ray diffraction, show that the SLs exhibit excellent period constancy and very abrupt interfaces.