Ion beam analysis of rare earth nitride thin films

We report compositional measurements on highly disordered GdN, DyN, ErN and SmN thin films, grown using ion-assisted deposition and capped with GaN AlN and Al, grown using the same technique. Ion beam analysis technique of RBS, PIXE and nuclear reaction analysis (NRA) were used to determine the composition of the capped films ex situ, and show that GaN and AlN protects the GdN, DyN and SmN films from oxidation over a timescale of at least a few days. NRA depth profiles indicate that oxygen is incorporated into the films during deposition and is located at the GaN/GdN interface. The ion beam analysis measurements showed that stoichiometric ratios can be obtained and oxygen impurities are significantly reduced by varying the film deposition parameters. The successful protection of the rare earth (RE) nitride films from oxidation allows for a reliable analysis of the RE films in the as-deposited state.