Single-crystal heteroepitaxial growth of PbxSn1-xTe films was achieved by r.f. sputtering deposition onto single crystals of germanium (both ?100? and ?111? orientations), although there is a large mismatch (~12%) in the lattice parameters between the grown film and the substrate. The structures of the r.f. sputtered films were investigated by high energy electron diffraction microscopy, electron surface replicas and scanning electron microscopy. Differences in the substrate temperature needed for the epitaxial growth on ?100? or ?111? orientations are attributed to the tendency of PbxSn1-xTe films to grow parallel to the (100) plane, which is the cleavage plane of the NaCl structure. This causes a mixed (100)-oriented phase in addition to the (111) orientation expected from the symmetry of the substrate surface in the case of (111) germanium substrates. Examples of the effects on the heterogeneous nucleation of the substrate temperature and deposition rate are shown for both orientations. The first stages of growth (initial reactions with the substrates) and the thickness and concentration profiles were investigated by ion beam backscattering analysis. Channelling techniques confirmed the high degree of order in the single- crystal structure of films deposited on large areas (~1 cm2).
Single-crystal heteroepitaxial growth of PbxSn1-xTe films on germanium substrates by r.f. sputtering
Fainelli;
1976
Abstract
Single-crystal heteroepitaxial growth of PbxSn1-xTe films was achieved by r.f. sputtering deposition onto single crystals of germanium (both ?100? and ?111? orientations), although there is a large mismatch (~12%) in the lattice parameters between the grown film and the substrate. The structures of the r.f. sputtered films were investigated by high energy electron diffraction microscopy, electron surface replicas and scanning electron microscopy. Differences in the substrate temperature needed for the epitaxial growth on ?100? or ?111? orientations are attributed to the tendency of PbxSn1-xTe films to grow parallel to the (100) plane, which is the cleavage plane of the NaCl structure. This causes a mixed (100)-oriented phase in addition to the (111) orientation expected from the symmetry of the substrate surface in the case of (111) germanium substrates. Examples of the effects on the heterogeneous nucleation of the substrate temperature and deposition rate are shown for both orientations. The first stages of growth (initial reactions with the substrates) and the thickness and concentration profiles were investigated by ion beam backscattering analysis. Channelling techniques confirmed the high degree of order in the single- crystal structure of films deposited on large areas (~1 cm2).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
