Study of Synchrotron Radiation Near-Edge X-Ray Absorption Fine-Structure of Amorphous Hydrogenated Carbon Films at Various Thicknesses

Abstract EN

The compositions and bonding states of the amorphous hydrogenated carbon films at various thicknesses were evaluated via near-edge X-ray absorption fine-structure (NEXAFS) and elastic recoil detection analysis combined with Rutherford backscattering spectrometry.

The absolute carbon sp 2 contents were determined to decrease to 65% from 73%, while the hydrogen contents increase from 26 to 33 at.% as the film thickness increases.

In addition, as the film thickness increases, the π ⁎ (C=C), σ ⁎ (C–H), σ ⁎ (C=C), and σ ⁎ (C≡C) bonding states were found to increase, whereas the π ⁎ (C≡C) and σ ⁎ (C–C) bonding states were observed to decrease in the NEXAFS spectra.

Consequently, the film thickness is a key factor to evaluate the composition and bonding state of the films.