Sputtering of Polycrystalline Copper and Silver by 30–170 keV Argon Ions

Abstract

Polycrystalline copper and silver have been sputtered by 30–170 keV singly ionized argon at various beam angles, and total yields (atoms/ion) have been measured as a function of energy and incident angle. Angular distributions of sputtered material about the target normal indicate a distribution approximately proportional to the cosine of the angle of emission, but with more material collected in the normal direction than for a strict cosine distribution. No significant variation of angular distribution with ion energy or with sputtering beam angle was observed. The yield appears to be independent of pressure, collector temperature, current, and current density. Erratic results were obtained when the target was not water cooled, and when the glass collector plates were not initially coated with a thin layer (∼50 Å) of evaporated metal.