Structural analysis of 6H-SiC(0001) surface by RHEED rocking curves

Surface structures of 6H-SiC(0 0 0 1)root3 x root 3R30 degrees and 3 x 3 re constructions have been studied by rocking curves of reflection high energy electron diffraction (RHEED) intensities in one-beam condition. The root3 x root 3R30 degrees reconstruction is observed by annealing the Si pre-depo sited specimen in the Si flux at 1030 degreesC for 5 min. The 3 x 3 reconst ructions is observed by annealing the Si pre-deposited specimen in the Si f lux at 1000 degreesC for 5 min and by successive annealing of the root3 x r oot3 surface in the Si flux at 940 degreesC for 5 min. Normal components of atomic positions and layer densities are determined by analysis with RHEED dynamical calculations for the root3 x root3. For the 3 x 3 surfaces, we d etermined surface normal components of atomic positions for three possible structure models. (C) 2001 Elsevier Science B.V. All rights reserved.