Cv. Budtz-jorgensen et al., Chemical and physical sputtering of aluminium and gold samples using Ar-H-2 DC-glow discharges, SURF COAT, 135(2-3), 2001, pp. 299-306
We present a series of sputtering experiments on aluminium samples performe
d with an Ar-H, DC-glow discharge at varying Ar-H, gas-composition, driven
at a discharge voltage of -300 V and a pressure of 0.2 mbar, in conjunction
with measurements of the corresponding ion-energy distributions of the ion
s bombarding the discharge cathode (Ar+, Ar2+, ArH+, H-2(+); and H-3(+)). S
imilar measurements on gold samples, which have been published, have shown
that the Au-sputtering efficiency of an Ar-H-2 glow discharge as a function
of gas-composition could be adequately described by the corresponding chan
ge in the measured ion-energy distributions, under the assumption of a pure
ly physical sputtering process. The experiments presented here show that th
is is not the case for aluminium (effectively Al2O3). In this case, a measu
red optimal gas-composition of 80% H-2 was found for Al-sputtering, while t
he energy-distributions suggest an optimum at 20% (as for gold). This clear
ly suggests that hydrogen-enhanced chemical sputtering is taking place. (C)
2001 Elsevier Science B.V. All rights reserved.