Practical investigations in the past few years have shown the promising nature of the use of the plasma-chemical method of etching silicon dioxide films during the production of integrated circuits. Nevertheless, with rare exceptions [1-3], the available studies were carried out without calling upon modern diagnostic methods for studying the plasma, not making it possible heretofore to determine the mechanism of plasma-chemical etching in sufficient detail, to reveal the limiting possibilities of the method, or to develop scientific and technical principles for the optimization of its use.