Abstract
This study implements the CMOS-MEMS Fabry-Pérot interference device (FPI) in standard TSMC 0.35m 2P4M CMOS platform by post-CMOS process. It might improve the performance of existing optical sensor, filters, and image sensors. The presented FPI could monolithically integrate with CMOS light sensor, and the single color reflective modulation is also achieved by color filter integration. The design was constrained by the design rule and the limited material in the specific layer-stacking. Following the principles, the concept in this thesis propose the stacking in Fabry-Pérot interference structure with the material of Poly-Si, Al, TiN, W, SiO2. The dual tunable cavities could decide the interference conditions to modulate the incident light. The features of this design are as follows, (1) two optical resonant cavities are provided by the transparent oxide layer and air-gap, (2) oxide thickness is determined by post-CMOS etching process, (3) tunable gap can be controlled by electrostatic force, (4) ring-type electrode is exploited as rib-reinforced structure for thin oxide membrane. In summary, the presented FPI could modulate optical intensity by varying the dielectric membrane thickness and resonant air-gap. Moreover, the thesis includes the theory analysis, optical design, simulation, fabrication, measurement. This CMOS-MEMS FPI device might be the component to approach “Integrated optics” for optical circuitry applications in the future.