Effect of deposition temperature on chemical composition and electronic properties of amorphous carbon nitride (a-CNx) thin films grown by plasma assisted pulsed laser deposition

The effect of deposition temperature and nitrogen inclusion in amorphous carbon (a-C) films, deposited by plasma enhanced pulsed laser deposition, on chemical composition and electronic transport has been studied. a-CNx films were deposited on Si (100) by pulsed ArF laser ablation of a graphite target, under N2 atmosphere. A radiofrequency (13.56 MHz RF) apparatus was used to generate plasma of excited nitrogen species, and its effect on nitrogen uptake and CNx film formation has been studied. Chemical and micro-structural changes associated to increased deposition temperature and nitrogen incorporation were examined by x-ray photoelectron spectroscopy; electrical properties were analyzed by the four-point-probe methods. Temperature-dependent conductivity measurements are tentatively interpreted and discussed in reference to chemical composition.