Hydrogen analysis of BCN films with resonant nuclear reactions

Hydrogen is one of typical contaminants in carbon-based films. It can strongly influence the mechanical, physical and chemical properties of the films. The analysis of hydrogen is therefore a crucial problem in the course of preparing the films with the required properties. Ion beam techniques using nuclear reactions are effective for the quantitative determination of hydrogen concentration. A specially designed spectrometer is employed for the detailed determination of hydrogen concentrations by detecting 4.43 MeV γ-rays from the resonant nuclear reactions 1H(15N,αγ)12C at 6.385 MeV. In this study, the BCN films were formed on silicon substrate with ion-beam-assisted deposition (IBAD), in which boron and carbon were deposited by electron beam heating of B4C solid and nitrogen was supplied by ion implantation simultaneously. The hydrogen depth profiling in the near surface region of BCN films were performed by employing RNRA. The mechanical properties of BCN films were evaluated using an ultra-micro-hardness tester. It has been confirmed that the hardness of BCN films becomes larger with the increase of the hydrogen concentration.