Reactive expansion of laser-induced boron/carbon plasma in ECR nitrogen plasma during the deposition of BCN films

The expansion of the boron/carbon plasma induced by pulsed laser ablation of B4C in the nitrogen plasma generated by electron cyclotron resonance (ECR) microwave discharge of N-2 gas was studied by optical emission spectroscopy (OES). DES measurements show that at the initial stages the mono-atomic species ablated from B4C are the dominant emitting species and after 0.5 mu s the plasma emission evolves to be dominated by the emission bands from nitrogen molecules and nitrogen molecular ions, revealing that the N-2 gas is highly excited by the hybrid processes of ECR microwave discharge and pulsed laser ablation. In addition to the emissions emitted from the species ablated from the target and present in the reactive background, C-2 and CN emissions are also observed. The characteristics of the emissions from various species provide an access to the reactive expansion of the boron/carbon plasma in the nitrogen plasma and the gas-phase reactions occurring in the plasmas during the deposition of BCN films by nitrogen plasma assisted pulsed laser deposition. The mechanisms for efficient incorporation of nitrogen in the films were also discussed. (C) 2011 Elsevier B.V. All rights reserved.