X-RAY PHOTOELECTRON-DIFFRACTION STUDY OF INTERMIXING AND MORPHOLOGY AT THE GE SI(001) AND GE/SB/SI(001) INTERFACE/

We used the XPD (x-ray photoelectron diffraction) and AED (Auger elect ron diffraction) from Ge core levels to probe the crystalline structur e of 3 and 6 ML of Ge epitaxially grown by molecular-beam epitaxy on t he Si(001) surface. In order to check the film tetragonal distortion a nd the pseudomorphic growth morphology, we used two different temperat ures of the substrate during the deposition: room temperature and 400 degrees C. Evidence for an interfacial intermixing has been found by m eans of the observation of the angular behavior of the intensity of th e emitted electrons. We also investigated the effects of Sb as a surfa ctant on such an interface. In this case indications of a laminar grow th of strained Ge overlayer with reduced intermixing is obtained when 1 ML of Sb is predeposited on the substrate. Furthermore making use of a multiple-scattering approach to reproduce the experimental XPD patt erns, a higher amount of accessible information on the morphology of t he interface, beyond the determination of the strain content, is obtai ned.