Experimental study of a surfactant-assisted SiGe graded layer and a symmetrically strained Si/Ge superlattice for thermoelectric applications

A method to grow high-quality SiGe graded buffer layer is presented. The ma in concept of the method is to use Sb as a surfactant when growing Sice gra ded layers. Compared with a Si0.5Ge0.5 graded sample without Sb surfactant, the Sb-assisted Si0.5Ge0.5 graded layer has much smoother surface and a si gnificantly lower threading dislocation density. Thermal conductivity of a symmetrically strained Si/Ge superlattice grown on Sb-assisted Si0.5Ge0.5 g raded layer is also presented. (C) 2000 Elsevier Science S.A. All rights re served.