Features of Zone Thermal Recrystallization of Germaniun Layers Grown on Silicon Substrates from a Discrete Source

We have proposed and investigated a new technique for growing thin uniform layers onto a large semiconductor substrates. The method uses the system of hexagonally arranged round local sources filled with liquid growth substance. The growth substance evaporates on very close substrate, which is removed from the discrete source by about 1 mm. In these conditions vapor pressure of the residual gases is reduced by two orders of magnitude. It is found that to obtain uniform thickness layers by the proposed technique it is strongly necessary that the distance between the discrete source and the substrate will be greater than the critical thickness lcr. It is shown that this parameters lcr increases with the increasing of radius of local sources and the distance between the local sources. For example, to achieve uniformity of better than 97% the critical thickness must be equal to lcr = 1.2 mm for a hexagonal arranged system of round local sources with the radius of r = 0.75 mm and the distance between the sources of h = 0.5 mm.