Near total reflection x-ray photoelectron spectroscopy: quantifying chemistry at solid/liquid and solid/solid interfaces. (8th September 2021)

• Record Type: Journal Article
• Authors: Martins, H P; Conti, G; Cordova, I; Falling, L; Kersell, H; Salmassi, F; Gullikson, E; Vishik, I; Baeumer, C; Naulleau, P; Schneider, C M; Nemsak, S
• Is Part Of: Journal of physics. Volume 54:Number 46(2021)
• Publication Date: 2021-09-08
• Subjects: x-ray photoelectron spectroscopy -- near total reflection -- solid/liquid interface -- solid/solid interface -- photoresist; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/ac2067
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: Near total reflection regime has been widely used in x-ray science, specifically in grazing incidence small angle x-ray scattering and in hard x-ray photoelectron spectroscopy (XPS). In this work, we introduce some practical aspects of using near total reflection (NTR) in ambient pressure XPS and apply this technique to study chemical concentration gradients in a substrate/photoresist system. Experimental data are accompanied by x-ray optical and photoemission simulations to quantitatively probe the photoresist and the interface with the depth accuracy of ∼1 nm. Together, our calculations and experiments confirm that NTR XPS is a suitable method to extract information from buried interfaces with highest depth-resolution, which can help address open research questions regarding our understanding of concentration profiles, electrical gradients, and charge transfer phenomena at such interfaces. The presented methodology is especially attractive for solid/liquid interface studies, since it provides all the strengths of a Bragg-reflection standing-wave spectroscopy without the need of an artificial multilayer mirror serving as a standing wave generator, thus dramatically simplifying the sample synthesis.