Fabrication process of a microstructures based on hydrogenated amorphous SiGe films for applications in MEMS devices

We present a fabrication process of microstructures using both boron-doped hydrogenated amorphous silicon and hydrogenated amorphous silicon-germanium (a-SiB:H and a-Si0.5Ge0.5B:H) films for applications in devices based on microelectromechanical systems (MEMS). These microstructures are fabricated through plasma enhanced chemical vapor deposition (PECVD) with a low temperature of 300°C at 110 kHz and a pressure of 0.6 Torr. The proposed microstructures have three different geometries (Diamond, cantilever and bridge) considering a single structural layer of 1 μm thickness and are fabricated using surface micromachining. The fabricated a-Si0.5Ge0.5B:H microstructures do not present sticking problems and have good mechanical stability, which can allow their use in MEMS devices. Our fabrication process with hydrogenated amorphous SiGe films is simple. This process decreases the residual stress of the microstructures and allows the metal deposition on the microstructures surfaces.