Studies on the structure and bonding state of nitric amorphous carbon (a-CNx) films by reactive rf magnetron sputtering

This manuscript reports on the structure, bonding states of nitric amorphou s carbon (a-CNx) films and its correlation with electrical, optical propert ies with post-annealing treatment. a-CNx films were deposited on Si(100) by reactive rf magnetron sputtering using a gas mixture of Ar and N-2. X-ray photoelectron spectroscopy revealed that there are two different C-N bondin g states where N is bonded to both sp(2) and sp(3) C atoms. The amount of N -sp(3) C bond is proportional to the N/C atomic ratio in a-CNx. As the amou nt of N-sp(3) C bond decreased with annealing, total sp(3)/sp(2) bond ratio , resistivity, density and refractive index also decreased. Compared to amo rphous carbon (a-C), a slow decrease tendency of total sp(3)/sp(2) bond rat io was observed in a-CNx due to thermal resistance of the N-sp(3) C bond. ( C) 2000 Elsevier Science B.V. All rights reserved.