LOW-TEMPERATURE EPITAXIAL-GROWTH OF SI0.5GE0.5 ALLOY LAYER ON SI(100) BY ION-BEAM-ASSISTED DEPOSITION

The first results were reported on low temperature epitaxial growth of Si0.5Ge0.5 alloy layer on Si (100) by ion beam assisted deposition. Nucleation and the growth of Si0.5Ge0.5 alloy layer had been investigated by atomic force microscopy and reflection high energy electron diffraction analysis. The Si0.5Ge0.5 alloy layer nucleated on Si (100) via Stranski-Krastanov (SK) mode. The Ar ion bombardment improved crystallinity and prolonged layer-by-layer stage of the SK mode. The epitaxial temperature was 200 degrees C lower than 550-600 degrees C in molecular beam epitaxy. In order to explain the mechanism of low temperature epitaxial growth E(Ar) (energy transferred to growing film by bombarding Ar ion, eV/atom) value was experimentally calculated. In conclusion, the ion bombardment induced dissociation of three-dimensional islands and enhanced the surface diffusion. The variation of tetragonal strain and its effect on electron mobility were taken consideration. Electron mobility increased with tetragonal strain as a result of band split.