COMPETITIVE MECHANISMS IN REACTIVE ION ETCHING IN A CF4 PLASMA

Studies of etch rates of sputtered SiO2 and single crystal silicon being reactively ion etched on a silica cathode in a CF4 plasma indicate that for SiO2 the etching process is dominated by an ion-assisted mechanism, whereas for silicon it is usually dominated by the neutral chemical component. It is therefore expected that, with a nonerodible mask, the etched profile for SiO2 is vertical, whereas that of silicon will usually be undercut and tapered. Scanning electron micrographs of patterns etched in SiO2 and silicon confirm the predictions. © 1979, The Electrochemical Society, Inc. All rights reserved.