Spectral analysis method for deriving RBS-like carbon spectra from the 12C(α,α)12C resonant reaction

This article presents a spectral analysis method that detects C using the high-sensitivity of the 4.26 MeV resonance of the 12C(α,α)12C nuclear reaction while avoiding issues arising from the peaky and asymmetric resonance shape, which complicates depth-sensitive C analysis. By averaging nuclear reaction spectra taken with a set of conveniently chosen He beam energies, we obtain C spectra with amplified intensity, but shape similar to Rutherford backscattering spectrometry (RBS) spectra. The latter fact allows intuitive reading of underlying C depth profiles without employing spectrum simulation software. The method was first applied to simulated samples whose nuclear reaction spectra were generated by SIMNRA, which allowed checking for method accuracy by comparison to corresponding simulated RBS spectra. As real examples of the method application, it was applied to detect depth-sensitive C signals from SiC substrates covered by SiO2 layers and from 50 nm hafnium-based films deposited on Si by metal-organic chemical vapor deposition.