Filaments used in HF CVD
These are SEM photos of three types of metal filament used for hot filament CVD of diamond. They have been growing diamond in a 1%CH4/H2 atmosphere for about 4 hours.
|Tungsten filament, showing the thin layer of WC formed at the edge.||Rhenium filament, showing cracks along the edge and a homogeneous cross section - no carbide.|
||Tantalum filament, showing cracks and plates along the edge - no obvious carbide.|