Abstract
The effect of primary beam current and electron spot size on the Auger image resolution and signal‐to‐noise ratio (S/N) have been determined for field emission and thermionic emission sources. It is demonstrated that by use of a FE source and nA primary beam currents, an Auger image resolution of less than 1000 Å can be obtained. The major limitation to Auger spatial resolution is attributed to backscattered electrons. A LaB6 source is clearly superior to FE sources at primary beam currents of greater than 1×10−8 A.