MODELING OF SILICON ETCHING IN CF4/O2 AND CF4/H2 PLASMAS

A one-dimensional radial flow reactor model that includes fairly detailed free radical gas-phase chemistry has been developed for the etching of silicon in CF4/O2 and CF4/H2 plasmas. Attention has been restricted to transport and reaction of neutral species. The model equations were solved by orthogonal collocation. The sensitivities of the model predictions to flow rate, inlet gas composition, electron density, silicon loading, and other factors have been examined. The major loss path for fluorine atoms is different in CF4/O2 and CF4/H2 systems, and this results in significant qualitative differences in the parametric sensitivities of the two systems. © 1990, The Electrochemical Society, Inc. All rights reserved.