A step toward calculating the uncertainties in combined GIXRF-XRR

Stéphanie Melhem (1) , Yves Ménesguen (1) , Emmanuel Nolot (2) , Marie-Christine Lépy (1)

1 LNHB (CEA, LIST) - Laboratoire National Henri Becquerel (CEA, LIST)
2 DPFT - Département Plate-Forme Technologique

The combination of XRR and GIXRF is used for the characterization of thin films and multilayered materials, since both techniques use similar measuring and data analysis procedures and combining them leads to more accurate characterization in terms of thickness, roughness, density and elemental composition. However, there is a major difficulty to determine the associated uncertainties, due to the large number of fitting parameters and more specifically, to the combination of the two methods with dramatically different dynamic ranges. In this paper, we propose a recursive method for the estimation of the uncertainties of the data from the GIXRF-XRR analysis, based on a Bootstrap statistical method. We applied this method on a one layer chalcogenide GST thin film with a carbon caping layer for which we found small uncertainties on the model parameters. We propose also a method for calculating the uncertainty on the solid angle of the detector based on Monte Carlo simulation.

Mots clés: dynamic range; uncertaintiy assessment; Bootstrap statistical method; chalcogenide; carbon caping layer; modelling; detector; Monte Carlo; simulation; particle transport; X-ray reflectivity; grazing incidence X-ray fluorescence; metrology; ionizing radiation; thin film; material characterisation; multilayered material; signal processing; data analysis procedures; measuring procedures; thickness; roughness; density; elemental composition; associated uncertainties

Domaines: Matière Condensée [cond-mat]; Instrumentations et Détecteurs [physics.ins-det]

Stéphanie Melhem, Yves Ménesguen, Emmanuel Nolot, Marie-Christine Lépy. A step toward calculating the uncertainties in combined GIXRF-XRR. X-Ray Spectrometry, 2023, 52, pp.412-422. ⟨10.1002/xrs.3377⟩. ⟨cea-04563756⟩