HIGH-RESOLUTION ELECTRON-MICROSCOPY AND X-RAY PHOTOELECTRON-SPECTROSCOPY STUDIES OF HETEROEPITAXIAL SIXGE(1-X) ALLOYS PRODUCED THROUGH LASER-INDUCED PROCESSING

Pulsed laser induced epitaxy has been used to produce graded heteroepi taxial SixGe(1-x) alloy layers on Si(100) wafers by melting an a-Ge fi lm, previously grown by laser induced chemical vapor deposition, toget her with part of the wafer itself. High resolution electron microscopy and x-ray photoelectron spectroscopy analyses of SixGe(1-x) alloys su ggest the formation of two sublayers; a strained one starting from the substrate up to Ge concentration of about 10-15 at. % and a partially relaxed one on top. The complete crystallization of the alloy without the formation of precipitates and with low threading dislocation dens ity, proves that the combination of these laser-induced techniques rep resents a new and alternative process for the attainment of high quali ty SixGe(1-x) heterostructures. (C) 1998 American Institute of Physics .