The heteroepitaxy of Ge on Si(100) by vacuum evaporation

Abstract
High quality Ge epitaxial growth has been attained on Si(100) substrates at relatively low temperatures, 350 and 440 °C, by a vacuum evaporation technique. Electrical property and structural quality for the Ge layer were evaluated by Hall measurement, x-ray diffraction, and electron beam diffraction. It is found that the growth layers are p type and that net acceptor concentration and mobility strongly depend on the layer thickness. Of particular significance is the fact that the acceptor concentration decreases most rapidly and hole mobility remarkably increases with the Ge thickness. The acceptor concentration and the mobility at a point larger than 0.7 μm from the lattice mismatched interface are 1.6×1016 cm−3 and 1040 cm2/V sec, respectively. Hole mobility varies as a function of T3/2 and T−3/2 below and above ∼100 °K.