Present State of Development of Laser‐Assisted Wide Angle Three‐Dimensional Atom Probe

Abstract

AbstractThree‐dimensional atom probe (3DAP) has been developed in our laboratory. In our instrument, the position‐sensitive detector with a diameter of 120 mm following a pair of microchannel plates (MCP) was set up at a distance of 110 mm in front of the apex of the sample. Our original preset‐type sample stage with a local microelectrode was adopted. The pulse laser, or voltage pulse, was used as a trigger for field evaporation. The pulse width of the laser was 180 fs at a wavelength of 1030 nm. The pulse width of the voltage pulse was less than 10 ns. The performance of our instrument was widely tested with the pure tungsten samples fabricated by the electropolishing and focused ion beam methods. The flight path compensation of detected ions, including the small inclination of MCP assembly, led to the good mass resolution approximately 220 (FWHM). By this compensation, we realized full 0.75 sr acceptable angle 3DAP. The detection efficiency of emitted ions was estimated to be about 50% from the three‐dimensional reconstruction images of samples. Copyright © 2010 John Wiley & Sons, Ltd.