Defect controlled diffusion in the epitaxial growth of germanium on Si(100)

The growth of germanium films on Si(1 0 0) substrates prepared by two diffe rent methods is studied using atomic force microscopy and reflection high e nergy electron diffraction. The first method uses a brief Ar+ sputter follo wed by annealing to desorb the remaining oxide, resulting in a Rat substrat e. The second method involves the pre-treatment of the sample with an oxyge n plasma discharge before annealing. Pre-treating the Si(1 0 0) surface wit h an oxygen plasma discharge can sometimes result in etch pits that dramati cally affect the growth of the germanium film. The diffusion length of germ anium on the pretreated sample at 750 K is estimated to be greater than or equal to 700 +/- 100 nm by measuring the size of island-free terraces surro unded by etch pits. (C) 2001 Elsevier Science B.V. All rights reserved.