Competitive Mechanisms in Reactive Ion Etching in a CF 4 Plasma

Studies of etch rates of sputtered and single crystal silicon being reactively ion etched on a silica cathode in a plasma indicate that for 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 is vertical, whereas that of silicon will usually be undercut and tapered. Scanning electron micrographs of patterns etched in and silicon confirm the predictions.