Work function contrast detection for testing the cleanliness of ion-bombarded surfaces in Auger microanalysis

Significant contrast differences between linescans in an energy-filtered total electron emission taken at several tens of electron-volts and at several hundreds of electron-volts show up remarkably small differences in surface chemical composition, i.e. local differences in the work function on a partially cleaned surface, so that comparison of such scans can be used as a test for the cleanliness of a rough surface. The comparison can be quantified by a single numerical quantity which allows one to monitor the cleaning process.