Enhanced hydrogen desorption from Si sites during low-temperature Si1-xGexgrowth by disilane and solid-Ge molecular beam epitaxy

A phenomenological model is proposed to explain quantitatively the interest ing compositional dependence on the Ge incorporation rate during low-temper ature growth of Si1-xGex by disilane and solid-Ge molecular beam epitaxy, b ased on enhanced hydrogen desorption from Si sites due to the presence of G e atoms. The hydrogen desorption rate constant for disilane on Si sites is fitted to an exponential function of Ge incorporation rate and a possible p hysical explanation is discussed. Simulated results are in excellent agreem ent with experimental data. (C) 1999 American Institute of Physics. [S0021- 8979(99)02109-X].