Spatial resolution in X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy (XPS) is a well established surface analytical technique capable of giving elemental and chemical state information for nearly all elements. Recent improvements in the sensitivity of the method have made spatially resolved XPS a viable technique with, at present, a resolution of 5-30 mu m in commercial instrumentation. The different methods are described and their application to semiconductor devices and materials is outlined with reference to spatial resolution and information in depth. Future prospects for imaging XPS are briefly discussed.