High precision determination of the InN content of Al1−xInxN thin films by Rutherford backscattering spectrometry

In this work a careful manual analysis of Rutherford backscattering spectrometry spectra is discussed to determine the InN content of Al1−xInxN thin films grown on GaN buffer layers. The main source of error arises from the fact that the low signal of Al is superimposed to the high signal of Ga from the GaN buffer layer. The uncertainties in the derived InN fraction are discussed. Furthermore, it is shown that channelling effects only have a minor influence on the compositional analysis of the studied films although they can significantly reduce the count rate and distort the shape of the spectra.