SURFACE CHARACTERIZATION OF SMOOTH HETEROEPITAXIAL DIAMOND LAYERS ON BETA-SIC(001)

Surface morphology of continuous heteroepitaxial diamond layers on bet a-SiC (001) has been characterized by various methods. From surface no rmal SEM images, the surface was so smooth that crystal boundaries wer e not clearly observed, but in AFM and Normarski optical microscope im ages, shallow gaps supposed to be remnant boundaries and wrinkles on t he surfaces were observed. On the other hand, isolated (001) surfaces before coalescence had no wrinkles and were smoother than the surface of continuous heteroepitaxial films. The wrinkles observed only on the continuous heteroepitaxial film are considered to be formed by strain caused by coalescence, and raise the new problem of heteroepitaxy whe n the degree of orientation is improved. (C) 1997 Elsevier Science S.A .