Low energy argon ion-enhanced removal of carbon from silicon dioxide surfaces with atomic deuterium

This work examines the interacting roles of Ar ions and D atoms in the removal of carbon from silicon dioxide surfaces. Auger electron spectroscopy is used to measure the relative amounts of carbon on the surface following exposure to either Ar ions, D atoms, or simultaneous Ar ions and D atoms at room temperature, with ion and atom fluxes on the order of 1013 cmy2 sy1. D atoms alone are unable to remove carbon. Low energy Ar ions, 140 eV, remove carbon at a rate linearly dependent on the ion flux. Compared to Ar ions alone, simultaneous bombardment with Ar ions and D atoms increases the removal rate by a factor of ;2.5. The removal rate is independent of ion energy in the range 80–140 eV.and temperature 300–500 K.. The enhancement in the removal rate for simultaneous ion and atom exposure is attributed the breaking of C-surface bonds by Ar ions and the simultaneous hydrogenation by D atoms. Multiple steps produce CD species that can x desorb upon subsequent ion collision and CD4, which will desorb spontaneously upon formation. q1999 Elsevier Science B.V. All rights reserved.