The morphology and structure of metalorganic phase epitaxy grown homo-epitaxial (100)ZnTe layers on high-quality substrates grown by the vertical gradient freezing method was reported. Growth below 350C led to surface ridging along a <110> in-plane direction of the epilayer, the morphology of samples grown at or above 350C depending instead on the Te:Zn ad-atom relative abundance. Nearly featureless morphology was observed for epilayers grown under Zn-rich or nearly stoichiometric surface conditions, whereas large pyramid-like hillocks develop on Te-rich surfaces, their density reaching up to 106–107/cm2. Hillock formation was supposed to be driven by Te ad-atoms experiencing a Schwoebel potential barrier at the step edges around spiral centers, the latter ascribed to partial dislocation pairs bounding stacking faults. Analysis of the X-ray diffuse scattering intensity around the (400) reciprocal lattice point of the samples demonstrated that stacking faults occurred in epilayers grown at or above 350C, their density increasing with growth temperature. The stacking fault average diameter on {111} planes was estimated to be 200 to 300nm.

Morphology and Crystallinity of Homo-Epitaxial (100)ZnTe - Interplay between Ad-Atom Stoichiometry and Defect Nucleation during MOVPE. N.Lovergine, M.Traversa, P.Prete, T.Di Luccio, L.Tapfer, A.M.Mancini: Journal of Crystal Growth, 2005, 275[1-2], e1189-95