Studies of solid surfaces at atomic resolution: Atom-probe and field ion microscopy

The structure and composition are basic information of a surface. Using a field ion microscope the atomic structure of a surface can be observed, whereas using a time-of-flight atom-probe the composition of a surface can be analyzed, often with true single atomic layer depth resolution. We present here a brief review of studies with this technique, emphasizing recent developments. These include: (1) Observation of surface atomic reconstructions. (2) Successful imaging of silicon surfaces of well ordered atomic structures. (3) Using ns pulsed-laser heating, atomic processes in atom transport and surface reconstructions can be studied in 5 ns steps with true atomic resolution. (4) By using ps pulsed-laser assisted field desorption for the atom-probe operation, dissociation of compound ions in high electric field by atomic tunneling can be studied with a time resolution of 20 fs. These and other new theoretical and experimental developments in atom-probe and field ion microscopy and its application to surface science will be briefly described, focusing especially on the atomic resolution and the quantitative aspects of these studies.