Etching process

Abstract

A method for etching a pattern within a silicon containing dielectric layer upon a substrate employed within a microelectronics fabrication, employing a plasma activated reactive gas mixture, with layer material etch rate, etch rate ratio and pattern aspect ratio controlled by controlling the gas composition. There is provided a silicon substrate formed upon it a patterned microelectronics layer over which is formed a silicon containing dielectric layer. There is placed the silicon substrate within a reactor chamber equipped with electrodes which is evacuated. There is then filled the reactor chamber with a reactive gas mixture consisting of an oxidizing gas and two reactive gases. There may be optionally included in the reactive gas mixture nitrogen and inert gases for control purposes, but excluded from the reactive gas mixture are oxidizing gases containing carbon and oxygen. There is then formed a plasma by supplying high frequency electrical energy to the electrodes within the reactor chamber to bring about a plasma activated reactive gas etching environment, where the conditions may be selected to optimize the desired etch rate and etch rate selectivity.