INFLUENCE OF RADIATION DAMAGE (MICROSCOPIC CAUSES) ON THE SENSITIVITY OF AUGER ELECTRON SPECTROSCOPY AND X-RAY PHOTOELECTRON SPECTROSCOPY.

When the spatial resolution of a technique is increased, the dose needed to obtain a given signal has to be increased and damage effects can occur. Consequently, there are three limits for the spatial resolution: those concerning the optics, the available incident flux, and damage to the material tested. First, these three limits in X-ray photoelectron spectroscopy (XPS) and electron-induced Auger electron spectroscopy (e-AES) are analyzed and compared. Then the minimum concentration detectable by XPS and s** minus AES is expressed as a function of the microscopic causes (ionization of atoms and molecules) of the radiation damage (defined by a cross-section Q). The differences between the techniques are strongly reduced, if the two are assumed to have the same spatial resolution. The intrinsic advantage of XPS over e** minus AES is one or two orders of magnitude only if high doses of X-rays are available. A strategy is deduced to perform Auger analysis of sensitive materials.