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 present 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) reconstructions on Si(100) double domain surface. The observed data at RT are compatible with a Stransky-Krastanov growth. For the two observed reconstructions we measured intensities of several non integer order peaks 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 analysis confirms the STM structure and the presence of two tin monolayers 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 reported incommensurate (4 x 1) reconstruction has also been observed.