Methods and devices for atom probe mass resolution enhancement

Abstract

In an atom probe or other mass spectrometer wherein a specimen is subjected to ionizing pulses (voltage pulses, thermal pulses, etc.) which induce field evaporation of ions from the specimen, the evaporated ions are then subjected to corrective pulses which are synchronized with the ionizing pulses. These corrective pulses have a magnitude and timing sufficient to reduce the velocity distribution of the evaporated ions, thereby resulting in increased mass resolution for the atom probe/mass spectrometer. In a preferred arrangement, ionizing pulses are supplied to the specimen from a first counter electrode adjacent the specimen. The corrective pulses are then supplied from a second counter electrode which is coupled to the first via a passive or active network, with the network controlling the form (timing, amplitude, and shape) of the corrective pulses.