Surface analysis with pulsed‐laser stimulated field desorption

Using a pulsed‐laser stimulated field desorption time‐of‐flight spectrometer, known as the pulsed‐laser atom probe, surface atoms and atomic layers of one’s choice can be mass analyzed one by one. In addition, it is an ion kinetic energy analyzer with which the binding energy of surface atoms can be measured. We have developed a high‐resolution system which measures flight time of each ion with a time resolution of 156 ps. With a flight path of ∼778 cm, this system has a resolution and accuracy of about one to two parts in 10⁵ in mass analysis, ion kinetic energy analysis, and ion reaction rate measurement. This system has been used to study the binding energy of surface atoms in well‐defined sites, formation of cluster ions and their magic and critical numbers, compositional variation across the interface of silicon and silicide layer, field induced surface states, field dissociation of compound ions, and other desorption phenomena. We describe here this high‐resolution system, how it is calibrated, and also a few of these studies.