Si x Ge 1-x ultrahigh-vacuum chemical vapor deposition on Si(111)(7×7) from GeH 4 /Si 2 H 6 mixtures

We report the results of a study on ultrahigh-vacuum chemical vapor deposition of SixGe1-x layers on Si(111)(7×7) with GeH4 and Si2H6 mixtures. Using combined scanning tunneling microscopy and X-ray photoelectron spectroscopy, structural properties, the growth kinetics and the composition of the deposited alloys are analyzed as a function of the growth temperature for two different GeH4:Si2H6 mixture ratios. The mutual influence of the precursors is shown by comparing the structures formed during deposition and the sticking coefficients of Si2H6 and GeH4 with results obtained from exposure of Si(111) to the pure gases.