Field emission and Raman spectroscopy studies of atomic hydrogen etching on boron and nitrogen doped DLC films

This research studies diamond-like carbon (DLC) films doped with both boron and nitrogen prepared by microwave plasma enhanced chemical vapor deposition (MPECVD). The as-prepared samples with various doping of boron and nitrogen species were characterized using a Raman spectroscopic technique, and the electron field emission of the films was measured. The electron field emission properties of the as-deposited samples at fixed nitrogen doping vary with boron content significantly. The results infer that only when proper dopants are incorporated, the electron conduction in the DLC films is improved and the electron emission is enhanced. From the analysis of Raman spectra, it is found that the field emission depends on the relative intensities of D- and G-bands as well as the D*-band (~ 1150 cm ^-1) and G*-band (~ 1500 cm ^-1) that co-exist in the films. Post-production modification of the as-deposited samples via thermal annealing and annealing with atomic hydrogen etching were also conducted in an effort to understand the electron field emission mechanism.