EFFECT OF METHANE CONCENTRATIONS ON SURFACE MORPHOLOGIES AND SURFACE-STRUCTURES OF (001) HOMOEPITAXIAL DIAMOND THIN-FILMS

Homoepitaxial diamond films were grown on misoriented (001) substrates with CH4 concentrations of 1%, 2%, and 6% in H-2. Reflection high-energy electron diffraction was used to characterize the surface structure. At 1% CH4, step-flow growth occurred with the surface dose to the single-domain structure. This growth mode is expected to produce films with fewer crystal defects. On the other hand, when grown with 2% and 6% CH4, growth hillocks and random growth morphology were observed with the double-domain surface structure, respectively. The surface morphologies and surface structures are considered to change due to lower mobility and shorter diffusion lengths of adsorbates at higher CH4 concentrations. (C) 1995 American Institute of Physics.