Mechanism of Nitrogen Incorporation into Amorphous-CNx Films Formed by Plasma-Enhanced Chemical-Vapor Deposition of the Doublet and Quartet States of the CN Radical

High-resolution CN(B 2 Σ + –X 2 Σ + ) emission spectra were observed for the various processes to form amorphous-CN x ( a -CN x ) films using the plasma-enhanced chemical-vapor deposition of the CN radical produced from the dissociative excitation reactions of cyanides. A strong correlation was confirmed between the electronic states of CN in the plasma and the bonding states of nitrogen atoms in the films. The 4 Σ + and 4 Π states of CN were the precursors of the one- and/or two-dimensional C=N and C–N network structures of the films with high nitrogen content, [N]/([N]+[C]) ≤0.5. The CN(X 2 Σ + ) state formed the C≡N terminations primarily, a part of which changed to the one-dimensional C=N network from the additive reactions. The above correlation was fully explained by the molecular orbitals and the electronic configurations for the relevant electronic states of CN.