Soft X-Ray Emission Spectra of Ru/B₄C Multilayers Measured Under X-Ray Standing-Wave Conditions for Non-Destructive Interface Characterization

Abstract

Nondestructive analysis of the chemical states of the interface in Ru/B₄C multilayers was achieved using soft X-ray emission spectroscopy in the B K and C K regions of the multilayer measured under X-ray standing-wave conditions. The Ru/B₄C multilayer samples were selectively excited by monochromatized undulator radiation under X-ray standing-wave conditions at an excitation energy of 386 eV with an incident angle of 16°. Symmetrical differences in spectral features were observed between the on-standing-wave-conditions and the off-conditions at 386 eV (the Bragg condition). This symmetrical spectral feature change demonstrates that the chemical state differences in boron and carbon atoms between the interface and internal B₄C layers are observable by soft X-ray emission measurements under the X-ray standing-wave conditions.