Effect of Nitrogen Concentration on Nanodiamond Film Characteristics for Electrode Application

摘要

Microwave plasma chemical vapor deposited (MPCVD) nanodiamond films are promising materials for field emission devices, microelectrodes, nanoelectronics, and NEMS applications due to the material properties such as smaller grain sizes, higher grain boundary density, higher sp~2 carbon content, and smoother surface morphology for material integration (1).rnNanodiamond films can be made more conductive, by several orders of magnitude, by addition of nitrogen gas (up to 20%) in the PECVD gas mixture (2, 3). Nitrogen incorporation during nanodiamond growth process has been shown to increase the sp~2 carbon content and reduce the film resistance (4). Yet another study using nanodiamond films grown using a CH_4/Ar/H_2/N_2 gas mixture revealed results consistent with previous observations, the nanodiamond film changed from poor to semi-metallic conductor as the N_2 incorporation was varied from 0-25% (5).rnIn this work, we examine the effect on the nanodiamond films of increasing nitrogen concentration over a wider range, from ~9% to ~37.5%, in the H_2/CH_4/N_2 gas mixture