Nitrogen doping of amorphous DLC films by rf plasma dissociated nitrogen atom surface bombardment in a vacuum

Abstract

Interpretations of recent (1999) theoretical first principles calculations in the literature based on the density functional theory using the local density approximation has led to suggestions that a low energy nitrogen surface bombardment of amorphous carbon films should lead to a reduction in the work function of the films. By applying a low energy nitrogen flux generated by a nitrogen plasma source to the surface of amorphous diamondlike carbon (DLC, a-C : H) films prepared by plasma enhanced chemical vapour deposition (PEVCD) in a vacuum, relatively high non-bonded nitrogen doping levels have been observed compared with DLC films prepared by other methods reported in the literature. The amorphous DLC films have been characterised by X-ray photoelectron spectroscopy and Raman spectroscopy before and after nitrogen bombardment. This novel processing route is expected to have an impact on residual stress relief and the field emission properties of amorphous DLC.