X-ray reflection spectroscopy of the HfO2/SiO2/Si system in the region of the O–K absorption edge

Abstract

The paper shows the importance of soft X-ray reflection spectroscopy as a non-destructive in-depth characterization tool of the local atomic structure of high-k dielectric planar HfO 2 /SiO 2 /Si systems. The data obtained in the region of the O -K absorption edge demonstrate that the variation of the glancing angle enables the depth profilometry of the sample. By using the Kramers -Kronig analysis the reflection spectra are transformed into absorption spectra, from which the local physico-chemical environment of oxygen atoms is deduced, allowing also the knowledge of the local atomic structure and point defects associated with a thin superficial layer. D

Reflectivity spectra as absorption resonant spectra: is it correct?

“…In many cases, e.g. for investigations of thin resonant layers or surfaces, the Mo ¨ssbauer or X-ray resonant spectra near the absorption edges are measured in reflection geometry at small grazing angles, or some larger glancing angles in the case of the soft X-ray region (Martens & Rabe, 1980;Greaves, 1990;Waki & Hirai, 1989;Andreeva et al, 1991Andreeva et al, , 2018Irkaev et al, 1993a;Isaenko et al, 1994;Kao et al, 1994;Filatova et al, 1995Filatova et al, , 2006Sacchi & Mirone, 1998;Neumann et al, 1998;Se `ve et al, 1999;Oppeneer et al, 2003;Bergmann et al, 2006;Goering et ISSN 1600-5767 al., 2010Smekhova et al, 2010;Domashevskaya et al, 2011;Mitsui et al, 2012aMitsui et al, , 2016Mitsui et al, , 2020Ro ¨hlsberger et al, 2012;Holldack et al, 2014;Haber et al, 2016Haber et al, , 2017Cini et al, 2018Cini et al, , 2020Majhi et al, 2018;Cucinotta et al, 2020;Engel et al, 2020;Okabayashi et al, 2021a;Yokota et al, 2021;Ogawa et al, 2022). These experiments were carried out at synchrotron stations, which supply investigators with angular collimated and energy-selective radiation.…”

Interference phenomena of synchrotron radiation in TEY spectra for silicon-on-insulator structure

“…The interpretation of the spectral dependencies of TEY from multilayers at glancing angles, where the reflectivity could not be ignored, has attracted minor attention up to the present. Reflectivity spectra near absorption edges in the soft X-ray region have been investigated in just a few works (Barchewitz et al, 1978;Bremer et al, 1980;Kaihola & Bremer, 1981;Jones & Woodruff, 1982;Andrė et al, 1984;Lyakhovskaya et al, 1988;van Brug et al, 1989;Waki & Hirai, 1989;Filatova et al, 1995Filatova et al, , 1999Filatova et al, , 2006. However, experiments at synchrotrons have presented ample opportunities for such measurements.…”