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

Abstract

High-resolution CN(B 2 + -X 2 + ) 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 + and 4 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 + ) 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.

Fabrication of a-CN_<i>x</i> films by RF-plasma decomposition of BrCN

“…The detailed description of the apparatus has been made in ref. [17]. A stainless-steel cylindrical chamber with two parallel-plate electrodes was evacuated up to 110…”

Dissociative Excitation Process of BrCN in the ECR Plasmas of Rare Gases

“…We have applied these reactions to the synthesis of a-CN x and a-CN x :H thin films, where the microwave (MW) discharge flow of Ar [11][12][13][14][15][16][17][18][19] and the ECR discharge flows of Ar [20,21] and He [22] have been used. These films have the following characteristics.…”

Ab initio investigation of high multiplicity optical transitions in the spectra of CN and isoelectronic species

“…These intensity anomalies indicate that the a significant portion of the CN radicals are produced in metastable quartet states. Recently, Ito and coworkers [6] have identified the possibility that the nature of the metastable quartet electronic states contributes to precursor-dependent behavior in the chemical vapor deposition of amorphous-CN x films. Although subsequent investigations have favored ion-mediated processes as the determining factor for film hardness [7], quantification of the quartet state population is desirable.…”