Preparation of amorphous CNx thin films by pulsed laser deposition using a radio frequency radical beam source

Abstract

Amorphous CNx thin films were deposited by pulsed laser deposition (PLD) combined with a nitrogen rf radical beam source which supplies active nitrogen species to the growing film surface. The dominant active nitrogen species are excited N2 molecules and nitrogen atoms. The deposited films were characterized by scanning electron microscope, x-ray photoelectron spectroscopy (XPS), Raman scattering, and Fourier transform infrared (FTIR) spectroscopy. Nitrogen content of the deposited films increased with increasing rf input power and N2 pressure in the PLD chamber. The N/C ratio 0.23 was obtained at 400 W of rf input power and 1.3 Pa. XPS N 1s spectra shows the existence of N–sp2C and N–sp3C bonds in the deposited films. The fraction of the N–sp3C increased with increasing of N2 pressure in the PLD chamber during the operation of radical beam source. FTIR and Raman spectra of the deposited films indicated that N≡C bonds in the films were few as compared to the other carbon and nitrogen bonds.