Abstract:
Atomic layer epitaxy (ALE) is used frequently in the fabrication of semiconductor heterostructures. The basic idea of ALE is to obtain self--regulated growth by alternate deposition of the different particle species. In the ideal case one expects a growth rate of one monolayer per ALE cycle. However, surface reconstructions which are common for II--VI semiconductors like e.g. CdTe lead to a deviation from the ideal behavior. For CdTe, there are indeed two temperature regimes: at low temperatures CdTe grows with a rate of one monolayer per cycle, whereas for higher temperatures the growth rate drops to $1/2$ monolayer per cycle. Kinetic Monte Carlo (KMC) simulations of a lattice gas growth model developed in our group suggest that the explanation of this temperature dependence requires both the influence of characteristic surface reconstructions and the additional presence of weakly bound Te atoms.