Unusual RHEED patterns of a homoepitaxial diamond (001) surface explained by surface tilt

Unusual reflection high-energy electron diffraction (RHEED) patterns were o btained on a homoepitaxial diamond (001) surface. A RHEED pattern with only Kikuchi patterns was observed on the [010] direction, while a RHEED patter n with the specular point missing was observed on the [010] direction, the opposite azimuth angle. In the [100] direction, perpendicular to the above azimuth angles, a RHEED pattern with the 040-040 Kikuchi band tilting from the normal angle to the horizontal shadow edge-line was observed. These pat terns are explained by the surface tilt, as in an echelette grating. The of f-angle of the surface was estimated to be 3 degrees from the RHEED pattern s. This study shows that RHEED is a powerful method for the simultaneous es timation of the surface structures, roughness, and tilt. (C) 2001 Elsevier Science B.V. All rights reserved.