Abstract
Optical MEMS utilized by microstructure and micromachine to construct various optical functions, the applications from simple barcode reader to sophisticated optical network, the development of micromachining open up the new applications and opportunities. From 1970, the development of Bulk micromachining shows the characteristic of the precision etching in single crystal silicon could be used for optical alignment. And silicon also as a wonderful mechanical material, therefore the actuated silicon machine could function as light manipulator. The Surface micromachining developed from 1990, could implement real 3D structure by folded-up assembly. The refining micromachine utilized by surface micromachining demonstrate various applications, however the static and dynamic deformation of those thinness structure limits the optical performance. Therefore, the DRIE machining is developed for high aspect ratio structure, but those uni-thickness structures also have the limitation from the perspective of motion. This thesis proposed a novel micromachining process, based on existing thin film technology and integrate DRIE and Bulk wet release to realize a multi-depth micromachining process. The proposed hybrid process provides three level machining depths monolithically; therefore the thin film structure has the flexure property intrinsically, and also could be a high stiffness/weight ratio structure utilized by proposed rib-reinforced technology for better dynamic characteristic. This thin film micromaching also could inherit the assembly technology of surface micromachining. This thesis expounds the precision is the essential of micromachining when apply to optical application, both the position accuracy of static structure and motion accuracy of dynamic structure. Therefore the assembly technology and its accuracy were discussed, and conclude this technology is suitable for quasi-static precision optical bench. Further， for dynamic optical bench, the essential elements include actuator, transmitting mechanism and passive component were fabricated by proposed hybrid process, and a novel high frequency scanning mirror as a vehicle to demonstrate the proposed dynamic optical bench. In concludes, an optical bench utilized by proposed hybrid process could potentially meet the requirement both static and dynamic applications.