Field emission of nanostructured amorphous SiCN films deposited by reactive magnetron sputtering of SiC in CH 4/N 2 atmosphere

Abstract

Nanostructured and amorphous silicon carbon nitride (SiC x N y ) films have been deposited by magnetron sputtering of silicon carbide under reactive gas environment. Gas mixtures containing methane and nitrogen with various ratios were used for deposition. Auger electron spectroscopy, X-ray photoelectron spectroscopy and micro-Raman spectroscopy were employed to characterize the composition and bonding structures, while scanning electron microscopy and transmission electron microscopy were used to investigate the microstructure of the SiC xN y films. As the methane/nitrogen ratio was increased, the SiC x N y films changed from mirror-like smooth films to column-like and ridge-like C-rich SiC x N y nanostructures. Micro-Raman studies also showed some blueshift and narrowing of the G band at higher methane concentrations, suggesting an increase in the short-range order of the graphite-like phase in the nanostructured films. The sharper geometric features of the nanostructured SiC x N y films and possibly the higher conductivity of the films led to an enhancement in field emission properties. A low turn-on field (<10 V μm −1) and high emission current density (>0.2 mA cm −2), as well as good temporal emission stability, have been achieved for the nanostructured SiC x N y films.