Reflection high-energy electron diffraction and low energy electron diffraction studies of the homoepitaxially grown diamond (111) and (001) surfaces

We have investigated the surface morphology and crystallinity of homoepitaxially grown (111) and (001) diamond by reflection high-energy electron diffraction (RHEED) and low energy electron diffraction (LEED). In the smoothest C(001)-2 x 1/1 x 2 surface, both the RHEED and LEED patterns show half-order diffraction beams which are characteristically observed as the reconstructed surface structures. Caution has to be exercised when judging the structure of a C(111) surface from a LEED (1 x 1) pattern, because its observation can encompass surface morphologies ranging from single-crystal to polycrystalline diamond. In contrast, surface roughness has a dramatic effect on the RHEED pattern. The RHEED patterns of the smoothest C(111)-1 x 1 surface, grown at 690 degrees C, indicate that the surface smoothness is thought to be the closest to the ideally flat surface compared with previously reported homoepitaxial C(111) surfaces. (C) 1999 Elsevier Science S.A. All rights reserved.