Synthesis of polycrystalline diamond at low temperature on temperature sensitive materials of industrial interest

Diamond film deposition at low temperature is of considerable interest in electronics. We report on the growth of high-quality microcrystalline and nanocrystalline diamond films by sulfur-assisted hot filament chemical vapor deposition at substrate temperature ∼440 °C. The effects of substrate temperature in the presence of sulfur on diamond growth and structure were investigated. The deposition rate was found to increase as the substrate temperature is reduced, accompanied by a reduction in grain size and roughness, while the quality factor decreased only slightly. When glass is used as a substrate instead of molybdenum, the diamond quality, grain size, and roughness increase. The deposition of diamond at this relatively low temperature is interpreted in terms of the profound changes induced by the presence of sulfur in the gas phase chemistry.