Patent ID: 11217424

Abstract:
In APT systems and methods, a sample is analyzed by concurrently applying different types of energy to the tip of the sample, thereby causing atom evaporation from the end of the tip. Evaporated atoms are analyzed to determine chemical nature and original position information, which is used to generate a compositional profile. To ensure an accurate profile, the applied energy includes: a D.C. voltage, which lowers the critical energy level (Q) for atom evaporation; first laser pulses, which are applied to opposing first sides of the tip near the end to further lower Q and which are phase-shifted so resulting standing wave patterns of heat distribution have energy maxima that are offset and below a threshold to avoid damage to tip side surfaces; and second laser pulse(s), which is/are applied to second side(s) of the tip near the distal end to reach Q and cause atom evaporation from the end.