Characterization of titanium nitride layers by grazing-emission X-ray fluorescence spectrometry

Grazing-emission X-ray fluorescence spectrometry is a new development in X-ray metrology instrumentation. The combination of wavelength-dispersive detection with a total-reflection geometry in the detection path allows thin layer characterization also for light elements. The technique was applied to analyze a series of titanium nitride layers, reactively sputtered using different View the MathML source flow ratios of the working gas. Composition, thickness and density of the layers result from fitting the experimental data to model calculations. It was found that above a critical flow value, the samples are slightly over-stoichiometric (with respect to nitrogen) with a considerably reduced density. The GEXRF method has potential both for complete layer characterization and for process control with layer density as the control parameter.