Carbon-K NEXAFS measurements of a-CNx films formed from decomposition of BrCN in electron cyclotron resonance plasmas of He, Ne, and Ar

► a-CNx films having high N content were formed by our original technique using the decomposition of BrCN with ECR plasmas of He, Ne, and Ar. ► Local structures and compositions of the films were studied by C-K NEXAFS and XPS. They were formed to vary with the kind of rare gases. ► A cyclazine-like two-dimensional structure is proposed to explain these variations.