Defect controlled diffusion in the epitaxial growth of germanium on Si(1 0 0)

The growth of germanium films on Si(1 0 0) substrates prepared by two different methods is studied using atomic force microscopy and reflection high energy electron diffraction. The first method uses a brief Ar+ sputter followed by annealing to desorb the remaining oxide, resulting in a flat substrate. The second method involves the pre-treatment of the sample with an oxygen plasma discharge before annealing. Pre-treating the Si(1 0 0) surface with an oxygen plasma discharge can sometimes result in etch pits that dramatically affect the growth of the germanium film. The diffusion length of germanium on the pre-treated sample at 750 K is estimated to be ≥700±100 nm by measuring the size of island-free terraces surrounded by etch pits.