HISTORY OF DESORPTION INDUCED BY ELECTRONIC-TRANSITIONS

Desorption induced by electronic transitions (DIET) encompasses electron- and photon-stimulated desorption (ESD and PSD) of atoms, molecules and ions from surfaces. In this paper, we focus on the key experimental and theoretical developments that have led to a fundamental understanding of DIET processes. We emphasize the effects of ionizing radiation, i.e., electrons and photons with energies greater than or similar to 10 eV. The first DIET studies were occasioned mainly by the observation of anomalous peaks in mass spectrometers and spurious signals in ionization gauges. These observations were followed in the early 1960's by systematic studies of Redhead, and Menzel and Gomer, who independently proposed a Franck-Condon excitation model for electron-stimulated desorption of ions and neutrals from surfaces. In the years after this seminal work, ESD and PSD developed as fields of active interest to surface scientists. In addition to providing insights into the fundamental mechanisms linking atomic motion and electronic energy dissipation at surfaces, DIET investigations are continuing to impact upon radiation damage processes in areas as diverse as X-ray optics, semiconductor electronics, surface analysis and synthesis of molecules in interplanetary space.