Directional growth of Ge on GaAs at 175 degrees C using plasma-generated nanocrystals

We demonstrate the directional growth of Ge on a GaAs {100} wafer at 175 degrees C using radio-frequency plasma-enhanced chemical vapor deposition at 13.56 MHz under conditions where nanocrystals are the primary contributors to film growth. High resolution transmission electron microscopy (HRTEM) verifies the transport of plasma-formed nanocrystals to the substrate surface where they are initially mobile. Furthermore, cross-sectional HRTEM images show directional growth on the GaAs wafer, wherein the incident Ge nanocrystals have adopted the orientation of the underlying lattice. (C) 2008 American Institute of Physics.