High rate reactive ion etching of Al2O3 and Si

Abstract

The reactive ion etch rate (RIE) of Al2O3-based ceramics, in a plasmax reactor with a gas mixture of 5 μm Ar and 2 μm Cl2, is temperature sensitive. The etch rate at room temperature (∠2600 Å/min) is essentially all physical sputtering. For T=250 °C, the etch rate increase to ∠8200 Å/min. This increase in etch rate is the ’’chemical’’ component of the total etch rate. By means of the same technique, etch rates up to 2.0 μm/min were obtained for Si. In contrast to physical sputtering, RIE of these materials has the advantage that the reaction products are volatile compounds. Redeposition problems should therefore be minimized. In addition, the increase in etch rate obtained by RIE can be used as a trade-off to optimize other process parameters.