Patterned platinum etching studies in an argon high-density plasma

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.