HETEROGENEOUS NUCLEATION OF COHERENTLY STRAINED ISLANDS DURING EPITAXIAL-GROWTH OF GE ON SI(110)

We report on the molecular beam epitaxial growth of Ge on Si(110) surf aces. High temperature cleaning (oxide desorption) results in the form ation of shallow faceted pits distributed randomly on the Si(110) surf ace. Deposition of Ge at temperatures between 600 and 725 degrees C le ads to preferential nucleation along the pit edges forming elongated i slands, which subsequently grow to compact three-dimensional coherent islands. The observation of strained islands in close proximity to eac h other offers insights into their nucleation behavior and strain rela xation. Our observations suggest heterogeneous nucleation as a possibl e method for fabricating assemblies of quantum dots. (C) 1997 American Institute of Physics.