Thin CuInS2 films prepared by MOMBE interfaces and surface properties

CuInS2 were prepared on Si 111 by MOMBE using standard MBE Cu and In sources and Ditertbutyldisulfide TBDS as an organic sulfur precursor. Samples were analysed in situ by XPS, LEED an UPS. Deposition at 250 C yields chalcopyrite films [1] with admixtures of CuSi2 and CuIn alloys. Deposition at higher temperatures up to 550 C was used to clarify the feasibility of the process. High quality LEED diffraction patterns show epitaxial growth but CuSi2 precipitations are still observed for deposition on Si 111 . A bufferlayer of indiumsulfide showed no considerable effect on the interface morphology. The obtained LEED pattern are in accordance with the epitaxial relation Si 111 CuInS2 112 . Even for temperatures as high as 550 C no incorporation of Carbon or residual hydrocarbons in the film or adsorbed at the surface were detected