Design And Fabrication Research Of MEMS-Based Electric Field Sensors

Three types of MEMS-based Electric Field Sensors (MEFS) using electron-induction principle are proposed in this thesis, which are bulk-micromachining laterally driven MEFS (BLM), surface-micromachining laterally driven MEFS (SLM), and bulk-micromachining transversely driven MEFS (BTM) respectively.Finite Element Method-based analysis is used to simulate the inducting charge under the specific electric field. After the induction simulation and analyzing the dynamic characteristics of the MEFS, we predict the output signal and the frequency range, which proves the feasibility of the parameters design. Two means of the fabrication methods are utilized in this thesis, one of which is the microfabrication process in our lab, the other is following t he s tandard p rocess flow i n commercial foundry with our original structural design. The SLM is fabricated by using the MUMPS standard process in MEMSCSP Inc Ltd, while the BLM is in our lab's fabrication flow which is based upon bulk-micromachining technology.We finished the design of the three types of the MEFS, the initial devices of the SLM and BLM by using surface and bulk m icromachining p rocess r espectively. A novel form of the metal membrane shielding electrodes array in BLM is proposed, which proves to be a simple way to realize the shielding-electrodes combining with the moving element of the device. We also design and realize the differential inducting electrodes to counteract t he common-mode noise. Aiming at the r elevant fabrication process, we launch several experiments to optimize the methods, including the anisotropic etching and anodic bonding technique.