Ge growth on Si using atomic hydrogen as a surfactant

We have examined the effect of adsorbed atomic hydrogen (H) on the evolution of Ge films on Si(001) and (111) substrates in solid-source molecular-beam epitaxy. The H flux was supplied separately from the Ge flux. By cross-sectional high-resolution transmission electron microscopy it was observed that H acted as a surfactant during growth, suppressing island formation of Ge on both substrates. The effect of the H surfactant on variation of the growth mode is also discussed.