Dry etching in rf generated plasmas is currently used in semiconductor manufacturing and development laboratories to pattern a number of films including silicon, silicon compounds, resist, and aluminum. In this review, the etching requirements of VLSI, for example, the requirements for anisotropic etching, selective etching, and clean etching will be discussed. Four etching tools which differ markedly in geometry, position of substrates, and operating conditions will be contrasted. The etching characteristics of each will be described and related to the physical features of the reactor. © 1982, The Electrochemical Society, Inc. All rights reserved.