Thermal Stability and Tribological Properties of Fluorinated Amorphous Carbon Thin Films Doped with Nitrogen

摘要

Nitrogen doped fluorinated amorphous carbon thin films(a-C:N:F)were prepared by radio frequency plasma enhanced chemical vapor deposition(rf-PECVD)under different deposited condition using CH4,CF4,and N2 as source gases.The thin films were annealed at different temperature.The influence of doped nitrogen on the chemical structure,tribological and thermal properties of thin films were investigated by Atomic force microscopy(AFM),Fourier transform infrared absorption spectrometry(FTIR),X-ray photoelectron spectrum spectra(XPS),and thermogravimetry(TG).The results indicated that the thin films presence a compact and smooth morphology surface after the nitrogen doped.After incorporation of nitrogen,the H atoms are replaced partially by the N atoms in the thin films.The degree of cross-linking of the carbon network in the thin films is enhanced.The chemical bonds of C=N,C≡N,and C—Nx(x=1,2,3)have formed in the films.The relative content of sp2 graphite phase increases.The thermal stability temperature of the films deposited at r=0.5(r=N2/[CF4+CH4+N2])is 420 °C.The tribological properties improve greatly,and the friction coefficient of the a-C:N:F thin films ranges approximately from 0.20 to 0.36.