Development of Hard X-ray Photoelectron Spectroscopy for Laboratory Use

A hard X-ray photoelectron spectroscopy (HXPS) instrument has been developed for laboratory use by combining a monochromatic Cr Kα focused X-ray source, a wide acceptance angle objective lens and a high energy electron analyzer. The Cr Kα X-rays excited by a micro focused electron beam at 20 kV beam voltage are diffracted by an ellipsoidal bent crystal monochromator and focused on the sample. A wide acceptance angle objective lens was integrated as the first section of an input lens of a hemispherical analyzer. A 9.9 μm diameter minimum X-ray spot size was achieved and the energy resolution of 0.56 eV was obtained by Au Fermi edge measurements. The maximum acceptance angle and angular resolution were 70o and 0.54o, respectively. The typical acquisition time is about 30 min for a wide energy survey spectrum and about 1 h for Si 1s angle resolved spectra obtained without tilting the sample. The application of this instrument for the analyses of overlayers and multilayer thin films is also discussed.