Preparation and properties of reactive-sputtered amorphous CNx films

We prepared amorphous CNx films by a rf reactive magnetron sputtering using ArN2 mixed gas and a graphite target. The nitrogen-carbon ratio x = NC in films determined by the XPS increased from 0.48 to 0.62 as increasing the nitrogen gas partial pressure ratio r = pN2(pN2 + pAr). Optical energy gap E0 obtained by the Taucʹs plots increased from 1.4 to 1.6 eV with the nitrogen-carbon ratio x. Dangling bonds density of a-CNx was 1018 to 1019 cm−3 from ESR measurement. Dc conductivity of a-CNx is very small. As irradiated Xe lamp, photoconductivity was observed. The hydrogenation of a-CNx was tried by a hydrogen-plasma treatment.