Abstract
This work aims to design a novel monolithic accelerometer on (111) substrate. A new micro fabrication process is proposed to integrate the electrode and spring-mass system on single wafer without bonding process. This accelerometer has spring with high aspect ratio and large lump mass, which can produce pure in-plane motion. In order to get large capacitance variation, a new design of differential electrode was also proposed. This comb-shape electrode also plays as mask for metal deposition. Furthermore, this process needs only two masks to define spring-mass system and electrode from front side and backside respectively. Anisotropic etching is then used to separate mass from electrode. This step forms a surrounding gap to the opening of the top layer, which insulates top and bottom electrodes automatically.