MICROMECHANICAL PROPERTIES OF DIAMOND FILMS DEPOSITED BY MICROWAVE-PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION

This paper reports on the study of mechanical properties of diamond films produced by microwave plasma chemical vapour deposition on silicon under different deposition conditions. The quality of films has been examined by scanning electron microscopy, Raman spectroscopy and Auger electron spectroscopy. Raman and Auger electron spectra show significant differences between the sp3 and sp2 bonding characters depending on the methane concentrations used in the deposition of diamond films. The microstructure of these films has a significant influence on the microhardness and elastic properties measured by a dynamic microindentation technique in a load range 0.4-10 mN. Changes in film quality have shown variations in these values, leading to a relationship between the microstructure and mechanical properties of these diamond films. The best results have been obtained for diamond films deposited at CH4 concentrations in H-2 of less than 0.5 vol.%, reaching hardness values of up to 42 GPa and percentages of elastic recovery of up to 84.5%.