Sampling depth of total electron and fluorescence measurements in Si L- and K-edge absorption spectroscopy

Abstract

High resolution Si L-edge and K-edge X-ray absorption near edge structure (XANES) spectra for SiO 2 on Si substrates have been recorded using total electron yield (TEY) and fluorescence yield (FY) techniques. The sampling depths of TEY and FY for Si L-edge and Si K-edge, respectively, have been investigated in the energy range 95–120 eV and 1830–1900 eV. The maximum sampling depth for TEY is found to be ∼ 5 nm for the Si L-edge and ∼ 70 nm for the K-edge regions. The FY sampling depth at the L-edge is ∼ 70 nm whereas for the K-edge, the sampling depth is several hundred nm. Based on these data, and using a theoretical model, electron escape depths for the TEY measurements in both energy ranges have been deduced.