Peculiarities of the growth kinetics of silicon-germanium alloy layers from silane and germane with an additional heated element in the vacuum chamber

To study the disintegration of the molecules of hydrides at the surface of the growing layer and their influence on the rate of the epitaxial process a model of the growth kinetics of Si1 - xGex alloy layers from silane and g ermane by the molecular beam epitaxy method with SiH4 and GeH4 gas sources is considered. Through comparison of numerical simulation data and experime ntal relationships, the steady-state growth kinetics has been studied and a comparative analysis carried out of the efficiency of entry of Ge(Si) atom s into the growing layer both in the presence of Si and Ge atomic flows in the reactor (the so-called hot-wire method) and in their absence. The growt h rates obtained with this method of epitaxial growth and with one of its m odifications where the use is made of a sublimating silicon bar as an addit ional heated element have been compared. Peculiarities in the behavior of t he dependence of the layer growth rate on its composition have been reveale d and explained. (C) 2000 MAIK "Nauka/Interperiodica".