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-ene rgy electron diffraction was used to characterize the surface structur e. At 1% CH4, step-flow growth occurred with the surface dose to the s ingle-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 wit h the double-domain surface structure, respectively. The surface morph ologies and surface structures are considered to change due to lower m obility and shorter diffusion lengths of adsorbates at higher CH4 conc entrations. (C) 1995 American Institute of Physics.