A scanning photoelectron microscope for materials science spectromicroscopy at the Pohang Light Source

Abstract

A Fresnel zone plate based SPEM (scanning photoelectron microscope) is in operation at the Pohang Light Source. Space resolution of the SPEM is typically less than or similar to 1 mum (0.4 mum in the best resolution) and the photon flux at the focused spot is similar to10(9) photons/s. The SPEM is working in the energy range between 400 and 1,000 eV. In taking images and spectra, the SPEM detects photoelectrons from the focused spot using a hemispherical analyzer with 16-channel detection capability at energy resolution of similar to 0.5 eV The SPEM also measures sample current, with which comparative x-ray absorption micro-spectroscopy is available in limited energy range with spectral resolving power (E/DeltaE) of similar to 3,000. The advantage of detecting sample current image and x-ray absorption spectrum at the Fe L-III-edge is demonstrated for understanding the effect of electrochemically deposited Zn layer on Fe substrate.