THE STRUCTURE OF GEXSI1-X/SI STRAINED LAYER SUPERLATTICES AND HETEROSTRUCTURES

A series of GeSi/Si strained layer heterostructures grown by rapid radiant heating, very low pressure chemical vapor deposition (RRH/VLP-CVD) on a Si(100) substrate have been studied for the first time. The results of XPS and AES studies indicate that the epilayer is a pure GeSi alloy with a homogeneous composition and binding energy values are the same as those of bulk Si and Ge, respectively. The XRD spectra show that the epilayer is a high-quality single crystal with a lattice plane spacing different from that of the bulk GeSi alloy predicted by Vegard's law and from that measured from polycrystalline diffraction. This means that the epilayer is a strained film. The RRH/VLP-CVD method has been developed to grow Ge(x)Si1-x/Si superlattices. The results of XTEM, XRD and Raman measurements show a well-defined periodic structure with strain in both the alloy sublayers and the Si sublayers. This means a high-quality strained layer superlattice has been obtained.