| This thesis focuses on the implementation of a surface micromachining fabrication process for electrostatically actuated MEMS micromirrors in the McGill University's Nanotools microfabrication laboratory. The process consists in fabricating the devices out of aluminum using photoresist as a sacrificial material. To this effect simple cantilever micromirror structures were designed. They were then modeled and simulated using finite-element analyses from the commercially-available software ANSYS. Finally, in order to validate the results of the new process, the same structures were fabricated out of polysilicon using the Multi-User MEMS Processes (PolyMUMPS) technology available through the Canadian Microelectronics Corporation (CMC). The theoretical and experimental results from the PolyMUMPS micromirrors were compared. The results at low voltages were similar, but they diverged for larger voltages and deflections, with the simulations usually predicting stiffer structures. The characterization of the structures fabricated with the Nanotools process indicated that they remained stuck to the substrate after the release process. Manipulation during testing caused some of them to be partially released, at which point they could be electrostatically actuated. With a better understanding of the aluminum properties and modifications to the original designs, one can fabricate viable aluminum structures using this process. Different areas of improvement as well as future directions for MEMS fabrication in this laboratory were also identified. |
