Charge stabilization and ion trapping under specimen isolation conditions during Sims analysis

Specimen isolation (SI), an extreme form of kinetic energy filtration, has been shown to be an effective tool for controlling the problems of sample charging and molecular interferences often encounted in secondary ion mass spectrometry (SIMS). In this study the mechanisms involved in the charge stabilization, under both positive and negative primary beam bombardment, were examined more closely. This was facilitated by the introduction of a resistor into the SI configuration, allowing for in situ sample potential control, and the use of computer simulations. The formation of low‐energy ion traps at the sample surface under extreme SI conditions was also directly recorded, showing good agreement with the computer simulations carried out.