Low temperature chemical vapor deposition of Si-based compounds via SiH3SiH2SiH3:: Metastable SiSn/GeSn/Si(100) heteroepitaxial structures

Growth of Si1-xSnx alloys on Ge1-ySny-buffered Si(100) was achieved via reactions of SnD4 and SiH3SiH2SiH3 at 275 degrees C. Kinetic studies indicate that unprecedented low growth temperatures are made possible by the highly reactive SiH2 groups. The authors obtain supersaturated metastable compositions (y similar to 25%) near the indirect to direct band gap crossover predicted by first principles simulations. Extensive characterizations of composition, structure, and morphology show that the SiSn/GeSn films grow lattice matched via a compositional pinning mechanism. The initial Raman observations of Si-Sn bond vibrations in a condensed phase are discussed in the context of simulated bond distributions in the alloys. (c) 2006 American Institute of Physics.