Ge deposition from digermane on the Si(100)-(2 × 1) surface

The initial deposition of Ge on Si(100) has been followed by TPD (temperature programmed desorption) and AES (Auger electron spectroscopy). The GeSi(100) surfaces were prepared from repeated cycles of chemisorption and thermal desorption of Ge2H6 on the Si(100) surface. Simultaneous exposures of UV light and Ge2H6 flux was shown to enhance the Ge deposit per chemisorption/flash cycle. The desorption of D2 from GeSi(100) has also been studied. The D2 desorption maxima shift to lower temperatures with increasing Ge coverage until a new low-temperature desorption state prevails. This fact provides a possible clue to explain the acceleration in growth rate observed during SiGe alloy growth by CVD when GeH4 is incorporated to the Si source gas.