THE CHEMISORPTION AND REACTION OF DICHLOROSILANE ON GE(100) AND GE(111) SURFACES

The reactions of dichlorosilane (SiCl2H2) with Ge(100) and Ge(111) are investigated with soft X-ray photoelectron spectroscopy excited by sy nchrotron radiation. SiCl2H2 is found to dissociatively chemisorb at a ll temperatures. At room temperature, the adsorbed layer is composed o f multiple silicon chlorides and hydrides. At exposure temperatures be tween 200 and 400-degrees-C, the surfaces are covered primarily by SiC l with some higher chlorides and unchlorinated Si also present. The sp ecific distributions of these species are slightly different on Ge(100 ) and Ge(111), with greater concentrations of higher silicon chlorides on Ge(111). For exposures in the range of 500 to 600-degrees-C, pure Si is deposited onto the surfaces, likely in the form of islands. For exposures at 700-degrees-C, Si is also interdiffused into the Ge subst rate.