X-ray Photoelectron Spectroscopy | Angle Resolved XPS

What is angle-resolved XPS?

Analysis of a thin oxide film on a metal at near-normal and near-grazing collection angles could produce spectra with a larger relative intensity of the oxide peak at the near-grazing emission angle.

The information depth for XPS is a few nanometers, depending upon the kinetic energy of the electrons and the material being analyzed. Angle-resolved XPS (ARXPS), however, is a technique that varies the emission angle at which the electrons are collected, thereby enabling electron detection from different depths. ARXPS provides information about the thickness and composition of ultra-thin films. Such measurements are non-destructive, unlike sputter profiling.

Three major reasons why angle-resolved XPS is useful

It can be applied to films that are too thin to be analyzed by conventional depth profiling techniques.
It can be applied to films that are irretrievably damaged by sputtering (e.g., polymers).
It is non-destructive and can provide chemical state information, unlike methods based upon sputtering.

Angle-resolved XPS measurements provide the following information:

Ordering of layers in an ultra-thin film.
Thickness of layers
Distribution of elements and chemical states within the film (depth profile reconstruction).

Get materials science and electron microscopy updates

‹Materials Science Learning Center

Angle-resolved XPS data acquisition

Angle-resolved XPS experiments are undertaken in a serial manner, by limiting the angular acceptance of the analyzer and stepping through a range of angles in turn. This is usually undertaken by tilting the sample with respect to the analyzer.