NUCLEATION AND GROWTH OF HETEROEPITAXIAL DIAMOND FILMS ON SILICON

The introduction of the bias pretreatment process for in-situ nucleati on of oriented diamond crystallites on silicon was an important step t owards heteroepitaxial deposition of single crystalline diamond films. However, the quality of these films is still limited mainly due to a significant orientational spread of the epitaxial grains around the pe rfect heteroepitaxial orientation. A further improvement of these film s requires an extensive description of the film texture immediately af ter the nucleation, of its development with increasing film thickness, and an improved insight into the mechanism responsible for the nuclea tion process. In this report our recent and new results on the heteroe pitaxial deposition of diamond on Si(001) and Si(111) and the subseque nt textural characterization by X-ray pole figure measurements are rev iewed. The possibilities and limits for improving the film quality by an appropriate textured growth step are discussed. Furthermore, optica l measurements inside tile plasma during the biasing step and nucleati on experiments using patterned substrates indicate that the high field strength above the surface and the resulting acceleration of ions pla y a dominant role in the formation of diamond nuclei.