Research of Micro-Inertial Device High-Aspect-Ratio Etching Parameters

This is mainly due to the high chemical reactivity and spontaneous etching nature of the fluorine radicals towards silicon, and the high volatility of the silicon fluorides as reaction products. Anisotropy can only be achieved by the inclusion of sidewall passivation schemes to the process. The existing approaches to deep reactive ion etching (DRIE) of silicon are distinguished by the way sidewall passivation is achieved, the key to anisotropy and overall performance of the etch process. Cryogenic etching and the so-called Bosch process with alternating etch and passivation cycles are the two most well-known high-aspect-ratio silicon etch processes and are discussed in this paper.