Effects of substrate bias on the structural and field emission properties of diamond films

The effects of bias on modification of the structure, the surface morphology, and the field emission characteristic of diamond films have been examined by introducing positive substrate bias voltage during the hot filament chemical vapor deposition (HFCVD) process. The nondiamond carbon content incorporated during deposition increased significantly and the surface morphology lost their unique facet shape with increasing substrate bias voltage. The increase of nondiamond carbon content is attributed to both the increase of substrate temperature and the excessive generation of CH_n radicals. The field emission properties were improved with increasing bias voltage.