Measurement of Active Species Density for Synthesis of Amorphous Carbon Nitrides: II. Formation of CN(X2Σ+) by Decomposition of BrCN

Abstract

The density of CN(X2Σ+) radicals, which are considered to be the precursor to the formation of amorphous carbon nitride films, was measured by laser-induced fluorescence (LIF) spectroscopy of the CN(A2Πi–X2Σ+), 4-0, 5-1, and 7-2 bands. The CN(X2Σ+) radicals were produced by the dissociative excitation reaction of BrCN with microwave (MW) discharge flow of Ar under the pressure of 0.1 Torr, and the LIF spectra were observed just downstream of the nozzle tip from which BrCN was introduced. The LIF intensity for the individual transition was evaluated by spectral simulation analysis and by calibration against the Rayleigh scattering intensity by Ar atoms. The CN(X2Σ+) density was evaluated to be 9.9×1017 m-3. This density was analyzed using the previously determined Ar+ density [H. Ito et al.: Jpn. J. Appl. Phys. 43 (2004) 7277], and it is suggested that the dominant production and loss processes of CN(X2Σ+) are BrCN+-e- recombination and quenching with BrCN, respectively.