Highly anisotropic selective reactive ion etching of deep trenches in silicon

Abstract

Abstract Reactive ion etching (RIE) of single crystal silicon using a gas mixture of SF 6 and C 2 Cl 3 F 3 in parallel plate electrode reactor was investigated. A detailed study of etching characteristics as functions of gas composition, rf power, pressure, self-bias voltage was performed. The results were explored in order to optimize deep trench RIE process. The optimized process resulted in a high etch rate, a good selectivity silicon-to-photoresist, a high anisotropy, a nearly vertical etch profile, and smooth surface morphology. This process was successfully used to fabricate silicon preforms for a replication technology of polymer-based devices.