Guidelines to the application of nuclear resonance to quantitative thin film analysis

The use of elastic nuclear resonances, including ¹²C(α, α)¹²C, ¹⁴N(α, α)¹⁴N and ¹⁶O(α, α)¹⁶O, provide a useful means of enhancing the sensitivity toward light elements using the same experimental setup as for Rutherford backscattering. Quantitative information about light element concentrations is only obtainable under certain conditions, and the use of simulation programs in conjunction with resonance analysis may often lead to erroneous results. By using resonance near the peak value of the cross section one may enhance sensitivity; however, this may result in a loss of precision, defined as day-to-day repeatability of the measurement. Conversely, using resonance in an energy regime in which the cross section varies less rapidly may more accurately predict the actual composition than standard RBS but prove less useful for low concentrations. We explore the importance of film thickness and composition and the variation in the incident beam energy toward the selection of the appropriate resonance regime, as well as discuss common sources of error.