Etching Silicon with Fluorine Gas

The feasibility of using fluorine gas to etch silicon for fabricating microcircuits has been studied. A long induction period is observed prior to etching. The induction period is probably related to the quality and thickness of the oxide layer. Etch rates (for Pf2 ~ 2 Torr) of ~90 and 5000 A/min are observed at 50° and 220°C, respectively. The reaction probability for F2 on silicon is 4 × 106 at room temperature. © 1979, The Electrochemical Society, Inc. All rights reserved.