Silicon Carbide Surface Micromachining Technology by Tetramethylsilane-Based Atmospheric Vapor Deposition

Systematic study on selective silicon carbide (SiC) deposition on SiN, SiO₂ and Si was performed. Poly-SiC was deposited by atmospheric pressure vapor deposition (APCVD) using tetramethylsilane (TMS), which allows easy handling and low temperature deposition. We found a process condition enabling the selective SiC deposition as well as a design guideline for SiC surface micromachining based on the selective SiC deposition. If both process condition and design guideline are used, continuous fine-grained SiC films are deposited on SiN and Si, while SiC islands are deposited on SiO₂. SiC films on SiN are used as the microstructures, and SiC islands on SiO₂ are lifted off by SiO₂ sacrificial etching. Finally, movable SiC microstructures were fabricated by the developed surface micromachining technology.