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 heteroepitaxial SixGe(1-x) alloy layers on Si(100) wafers by melting an a-Ge film, previously grown by laser induced chemical vapor deposition, together with part of the wafer itself. High resolution electron microscopy and x-ray photoelectron spectroscopy analyses of SixGe(1-x) alloys suggest 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 density, proves that the combination of these laser-induced techniques represents a new and alternative process for the attainment of high quality SixGe(1-x) heterostructures. © 1998 American Institute of Physics.