High- and low-energy x-ray photoelectron techniques for compositional depth profiles: destructive versus non-destructive methods

Abstract

Hard x-ray photoelectron spectroscopy (HAXPES), angle-resolved x-ray photoelectron spectroscopy (ARXPS) and x-ray photoelectron spectroscopy (XPS) with simultaneous Ar+ bombardment are used to obtain chemical information and concentration depth profiles of thin film oxides on Cr, Al, Si substrata and to explore the capabilities of analyzing buried interfaces at depths above 10 nm in Cr–O–Al thin films mixed oxides deposited on Si substrata. ARXPS and HAXPES are non-destructive techniques and within the photon energy range (7.5–15 keV) and the emission angle range (0◦–70◦) used, both techniques provide equivalent information, ARXPS being more sensitive to the surface morphology. XPS and simultaneous sputtering with Ar+ is a destructive technique and effects such as atomic mixing are unavoidable; however, the comparative study with HAXPES allowed the measurement of key parameters for the understanding of the ion–matter interaction such as the mixing extent and the interface broadening.