Case Studies of XPS and HAXPES analysis Based on the Differences in Information Depth between Al Kα and Cr Kα

Abstract

In X-ray Photoelectron Spectroscopy (XPS), the information depth of photoelectrons using Al Kα (energy: 1486.6 eV) is approximately 5–10 nm. In contrast, Hard X-ray Photoelectron Spectroscopy (HAXPES), such as Cr Kα (5414.8 eV), which utilizes higher-energy X-rays, can extend the information depth up to about three times that of Al Kα. The deeper information depth of the Cr Kα can be used to avoid damage caused by sputtering. Additionally, combining HAXPES with angle-resolved measurements provides the chemical and elemental distributions from deeper regions. This article introduces applications of these measurement techniques using actual samples.