Sputtering measurements on controlled thermonuclear reactor materials using Auger electron spectroscopy

Simultaneous auger electron spectroscopy and ion sputtering have been used to measure the sputter yield, S (atom/ion), for Ar+ on carbon, tungsten, niobium, and silver in the energy range from 0.5 to 1.5 keV and for H+ on tungsten, carbon, and silver at 11 keV. All measurements were performed on thin films, ranging in thickness from 150 to 6000 A, which were maintained at room temperature during bombardment. These films were produced by vacuum vapor deposition, and the thicknesses were measured by surface profilometry. The auger electron signals were used to determine the time required to etch through a film; from these measurements and a knowledge of the ion current density, the sputter yield was determined. For Ar+, 0.7 less than or equal to S less than or equal to 5.1 and for H+, 0.004 less than or equal to S less than or equal to 0.04 for the various materials studied in this energy range. Agreement with earlier experimental results is generally within +-25 percent