Auger analysis of Si sputtered with Ar + ions in an F 2 ambient

Abstract

Ar + ion sputtering of undoped polycrystalline Si films in an F 2 ambient has been studied using in-situ Auger electron spectroscopy. An enhancement to the physical sputtering yield was observed at all energies from 300 to 2000 eV with an Ar + ion beam current of 10 microA/cm 2 and F 2 pressure of 3.2 × 10 −5 Torr. The enhancement increased at higher energies, while the F surface coverage decreased. A second order mass balance model is proposed to explain the F coverage and sputter yield data. At a fixed ion energy, the chemical yield appears to be proportional to the square of the F surface coverage.