ISO/AWI TS 25739

Surface chemical analysis — Electron spectroscopies — Work function measurement by ultraviolet photoelectron spectroscopy

Scope

This technical specification offers an overview of the measurement of the work function (WF) using ultraviolet photoelectron spectroscopy (UPS). It covers the selection of an appropriate spectrometer for WF measurement, calibration of the UPS energy scale, optimization of sample bias, determination of the secondary electron cutoff, and consideration of associated uncertainties. The RRT study for WF measurement utilizes samples that are both electrically conductive and flat across the observed area, including examples such as a gold (Au) film on a silicon wafer and highly-oriented pyrolytic graphite (HOPG).
This technical specification provides guidelines for measuring the work function (WF) using ultraviolet photoelectron spectroscopy (UPS). The scope is limited to electrically conductive and uniformly flat samples. This specification covers the following key aspects: (a) an overview of WF measurement, (b) sample preparation, (c) spectrometer settings, (d) sample bias optimization, (e) data analysis, (f) associated uncertainties, (g) results from round-robin tests (RRT), and (h) references. The RRT results confirm the consistency and reliability of WF measurements on gold (Au) films on silicon wafers and highly-oriented pyrolytic graphite (HOPG) across multiple laboratories.