Microwave plasma CVD of high quality heteroepitaxial diamond films

High purity diamond films exhibiting localised heteroepitaxy have been produced in a custom built microwave plasma reactor. The purity of the films has been determined by laser ionisation mass analysis, cathodoluminescence and Raman spectroscopy. The growth of this material occurs in a ring on the substrate with the area of aligned growth being approximately 25%, of the total deposited area. The grain size of the films is typically 3 to 4 µm. FTIR spectroscopy has been used to study the formation and thickness variation of the silicon carbide layer produced during the pretreatment and bias stages of the growth process. The average thickness of the silicon carbide in the region of epitaxial growth is only a few atomic layers after the final growth process.