Diamond Growth by Hot Carbon Filament Chemical Vapor Deposition

Diamond depositions from hydrogen-methane-acetone mixtures using hot carbon filaments as a thermal source have been performed. Depositions on both the carbon filaments and the silicon substrates have been observed. Stratic pyrolytic-graphite (PG) coatings were observed on the carbon filaments at temperature above 1800°C. Addition of oxygen from acetone enabled diamond growth on silicon substrates by pitting the PG coatings. Diamond growth rate on substrates is about 0.1-0.2 µm per hour resulting from a major hydrocarbon deposition on the carbon filaments. The diamond particles deposited on the substrates are about 1 µm in size and have cubo-octahedron shape consisting of smooth {100} and rough {111} faces. The rough {111} faces consist of triangular tiles and pits, resulting from the low carbon concentration near the growth planes. This method provides a contamination-free, PG-coated and durable carbon filament for diamond growth and for bias enhanced diamond growth.