Abstract:
The temperature dependence of the main kinetic parameters that determine the rate of pyrolysis of adsorbed germane molecules on the surface of the growing germanium layer is analyzed in an interval of growth temperatures of 300–700$^{\circ}$C. The degree of coverage of the germanium surface with hydrogen and radicals of germane molecules is estimated. A relationship between the characteristic rate of pyrolysis of hydride molecules and the capture rate of molecules on the surface and the rate of incorporation of Ge atoms into the growing layer is established. The temperature dependence of the rate of decomposition of molecular fragments on the germanium surface exhibits nonmonotonic behaviour, the type of which depends on temperature regimes and the stage of the sorption process at which the surface captures hydrogen from the adsorbed hydride molecule. The pyrolysis characteristics of germane are compared with the corresponding characteristics of the pyrolysis of silane molecules. It is found that an increase in the concentration of working gases in the growth chamber substantially affects the catalytic properties of the growth surface.
Keywords:chemical epitaxy, Ge hydrides, surface pyrolysis, molecular and surface hydrogen, kinetic parameters.