Fullerene-like nano-crystalline CNx films and its characteristics of field electron emission

CNx films were prepared by using microwave plasma-enhanced chemical vapor phase deposition. As-deposited films were analyzed by x-ray photoelectron spectroscopy, x-ray diffraction, scanning electron microscopy and Raman spectroscopy. Field electron emission characteristics of thin films were studied. Experimental results indicate that the film structure and properties of the field electron emission are related to flow ratio of N-2 to H-2 while the flow rate of CH4 was kept at 8 seem. When the flow ratio of N-2 to H-2 was 50/50 seem, the obtained film had a nano-crystalline graphitic structure with curved basal planes (fullerene-like structure) and excellent properties of field electron emission. The turn-on field decreased to 1.1 V/mum. At an electric field of 5.9V/mum, the average current density was 70muA/cm(2) and emission sites density was larger than 1 x 10(4) cm(-2).