Sputtering of Metal Surfaces by Ion Bombardment

Abstract

The emission of target particles under the impact of neutral or charged particles on metal targets has been the subject of investigation for more than a century. Thus it was realized several decades ago that the sputtering process played an important role in gas discharges. As seen from the excellent survey of the field, up to 1955, given by Wehner [760], most of the older data are more qualitative in character because of inadequate control of experimental conditions (as explained in section 10.2). However since the appearance of Wehner’s summary*, numerous studies under more controlled conditions have been conducted. These have led to significant new quantitative results which revise many of the conclusions drawn from qualitative older data. The astonishingly rapid increase of interest in sputtering phenomena over the last few years may be explained by the increased recognition of the important role the sputtering process plays in such fields of activity as thermo nuclear fusion plasmas (e.g., sputtered wall particles may cause unde sirable cooling effects in the plasma), the corrosion of surfaces of satellites and ion-propulsion electrodes, ion getter pumps, the controlled deposi tion of thin films of almost any material, and surface cleaning.