Low‐Angle X‐Ray Photoelectron Spectroscopy in the Analysis of Gold Nanolayers

X‐ray photoelectron spectroscopy (XPS), a method of surface analysis, when applied at low‐incidence angles, as in total reflection x‐ray photoelectron spectroscopy (TRXPS) and grazing incidence x‐ray photoelectron spectroscopy (GIXPS), enhances the sensitivity of photoelectron yield detection and enables surface depth profiling. The presented research focuses on applying the x‐ray photoelectron spectroscopy and the total reflection x‐ray photoelectron spectroscopy to analyze gold (Au) nanolayers with thicknesses of 10, 50, and 100 nm, deposited on a silicon (Si) substrate. The main objective was to determine the elemental composition and surface uniformity of the nanolayers and to evaluate detection limits of the XPS method for different glancing angles and various nanolayer thicknesses. X‐ray photoelectron measurements were performed both for the non‐total (35° and 10° angles) and the total reflection (2.4°) regime. The XPS spectra analysis focused on investigating photoelectron peaks. The following quantities were obtained: binding energy of the electrons, the intensity and full width at half maximum of photoelectron peaks, and the background level. Finally, the elemental composition of the nanolayer surface was determined. In the study, the homogeneity of the nanolayers was investigated. For the analyzed samples, this quantity, defined by the coefficient of variation of element concentration, was in the range from 0.8% to 3.3%, depending on the nanolayer thickness. The detection limit of the XPS/TRXPS measurements for different photoelectron peaks was obtained with values ranging from 0.025 at.% to 3.473 at.%. In addition, angular‐dependent GIXPS photoelectron yields were modeled for the Au layers with a thickness of 10, 50, and 100 nm, providing insight into how layer thickness affects signal intensity.