Interactions of slow ions and atoms with surfaces. Electron emission, sputtering, and novel applications

Full text: Impact of slow ions and atoms (typical impact velocity below one atomic unit) on a solid surface gives rise to numerous elastic and inelastic processes, some of them already known since more than a century (electron emission, sputtering) but still just fairly well understood. There are many important applications in plasma- and astrophysics, gas discharges, single particle detection, surface analytics, -modification and -structuring, etc. Both the type of interaction during close surface contact and the resulting collisional products (scattered projectiles with and without charge exchange, ejected electrons, photons, sputtered and desorbed target atoms, molecules and clusters) depend critically on the projectile species (kinetic energy, structure, charge state/internal energy), the scattering geometry and the target surface (metal, semiconductor, insulator; poly-or mono-crystalline, atomically clean or gas-covered). Recently some new experimental techniques have been introduced and applied to study relevant processes in more detail than hitherto possible, which has resulted in considerable progress in their understanding. After a short introduction into the most prominent reaction mechanisms, which govern slow ion-surface interaction, we will concentrate on the following two areas and their possible applications. (a) Electron emission by atoms and slow singly and multiply charged ions. (b) Multicharged ion induced surface defects ('potential sputtering')