Abstract
This study investigates the effect of ammoniamethane (NH 3 CH 4 ) mixtures on characteristics of nitrogen-doped amorphous hydrogenated carbon (a-C:H(N)) films prepared by plasma enhanced chemical vapor deposition. The a-C:H(N) films with identical thickness are deposited on p-type silicon (p-Si) substrates using different NH 3 /CH 4 ratios. These a-C:H(N)p-Si junctions are a potential candidate to use in electronic or photoelectronic devices. The microstructures, optical properties, and mechanical properties of a-C:H(N) films are evaluated. Furthermore, the residual stresses in a-C:H(N)films, and also, the current density-voltage and capacitance density-voltage behaviors of a-C:H(N)p-Si devices are investigated. Experimental results indicate that as the NH 3 /CH 4 ratio increases from 0 to 0.2, the nitrogencarbon ratio increases from 0 to 5.4. The nitrogen-carbon bonds, nitrogen-hydrogen bonds, and sp 2+ carbon fraction of carbon films enlarge with increasing NH 3 CH 4 ratio, while the deposition rate, ordered degree, optical band gap, reduced Youngs modulus, hardness, and residual stress of carbon films decrease. The a:C:H(N)p-Si device has an optimum electrical property at the NH 3 /CH 4 ratio of 0.15 (or at the NC ratio of 4.7). Finally, the results of this study are compared with those reported in literatures. © 2011 The Electrochemical Society.