Plasma etching of platinum was investigated using a high-density surface-wa
ve argon plasma operated in the low pressure regime. The substrate was RF b
iased up to 150 V. The influence of the ion density and of the DC selfbias
voltage on the sputter-etching characteristics was investigated at a gas pr
essure of 1 mTorr. It was found that, at this low pressure, the etch rare i
s an increasing function of both the ion density and the self-bias voltage.
High etch rates with a good selectivity over resist, good Pt sidewall angl
e and fence-free submicron features have been achieved using bias voltages
lower than 150 V.