EPITAXIAL-GROWTH OF PBTE ON (111)BAF2 AND (100)GAAS

The growth of PbTe on cleaved (111)BaF2 and polished (100)GaAs substrates has been studied by reflection high energy electron diffraction. For (111)BaF2 the nucleation orientation is always (111) whereas for (100)GaAs both (111) and (100) orientations occur. Due to the difference in thermal expansion coefficients between PbTe and GaAs, for growth temperatures of about 300°C, microcracks appear at room temperature. The epitaxial layers were examined by X-ray diffraction and from an analysis of the observed line-shapes a layer roughness is deduced.