Energy dependence of non-Rutherford proton elastic scattering spectrum for hafnium nitride thin film

The energy dependence of the backscattering spectrum of non-Rutherford proton elastic scattering spectrum for a hafnium nitride (HfN) thin film was investigated. The purpose of the study is to demonstrate the feasibility of proton elastic scattering at 1.6 MeV as a tool for compositional analysis of transition metal nitride films on a silicon substrate. A HfN thin film deposited on a silicon substrate was analyzed by a common Rutherford backscattering spectrometry (RBS) with an α beam at the energy of 1.98 MeV, and also by a proton elastic scattering at the energies between 1.53 MeV and 1.61 MeV. The results of two measurements were compared, and a good agreement for nitrogen composition was obtained when the proton energy was higher than 1.59 MeV. It was found that non-Rutherford proton elastic scattering can be used for the compositional analysis of HfN thin films with the thickness up to 230 nm. In analyzing a thicker film, careful observation is necessary.