Deep Reactive Ion Etching (DRIE) of High Aspect Ratio SiC Microstructures Using a Time-Multiplexed Etch-Passivate Process
High aspect ratio silicon carbide (SiC) microstructures are needed for microengines and other harsh environment micro-electro-mechanical systems (MEMS). Previously, deep reactive ion etching (DRIE) of low aspect ratio (AR ≤1) deep (>100 *m) trenches in SiC has been reported. However, existing DRIE processes for SiC are not well-suited for definition of high aspect ratio features because such simple etch-only processes provide insufficient control over sidewall roughness and slope. Therefore, we have investigated the use of a time-multiplexed etch-passivate (TMEP) process, which alternates etching with polymer passivation of the etch sidewalls. An optimized TMEP process was used to etch high aspect ratio (AR up to 13) deep (>100 *m) trenches in 6H-SiC. Power MEMS structures (micro turbine blades) in 6H-SiC were also fabricated.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
L. J. Evans and G. M. Beheim, "Deep Reactive Ion Etching (DRIE) of High Aspect Ratio SiC Microstructures Using a Time-Multiplexed Etch-Passivate Process", Materials Science Forum, Vols. 527-529, pp. 1115-1118, 2006