X-RAY-DIFFRACTION STUDIES OF EPITAXIAL SN INDUCED RECONSTRUCTIONS ON SI(100) SURFACES

Tin on Si(001) surfaces presents a complex phase diagram with several reconstructions as a function of metal coverage. In this paper, we pre sent X-ray diffraction studies of the room temperature tin deposition process and of the annealed high coverage c(8 x 4) and (5 x 1) reconst ructions on Si(100) double domain surface. The observed data at RT are compatible with a Stransky-Krastanov growth. For the two observed rec onstructions we measured intensities of several non integer order peak s at different values of the perpendicular momentum transfer. We will discuss the Patterson maps obtained by in-plane data by comparing them with the structure inferred by STM mensurements. A preliminary data a nalysis confirms the STM structure and the presence of two tin monolay ers in the case of the (5 x 1) reconstruction. In the case of the c(8 x 4), the STM model is not compatible with our data set. A never repor ted incommensurate (4 x 1) reconstruction has also been observed. (C) 1998 Elsevier Science B.V.