Abstract

This thesis concentrates primarily on optimum design and fabrication of novel MEMS (micro-electro-mechanical systems) infrared gas sensors. It deals with the thermal, electrical, optical and mechanical response for a spectroscopic gas sensor based on MEMS surface textured technologies. An overview of the theories of conventional and novel MEMS infrared gas sensors is presented. Two important surface modification technologies: Photonic Crystal (PC) and Surface Plasmon (SP) for the proposed devices as well as the SP dispersion relation are discussed. The structures, materials, geometries, and electrical properties of the devices for the generation of single and narrow band mid-infrared light source with high transmission efficiency are studied. Plane Wave Methods (PWM) are used to simulate Photonic Bandgap (PBG) and Finite Difference Time Domain (FDTD) methods are used to simulate the function of the proposed devices. Silicon on isolator (SOI) technology is used to design and fabricate the proposed device onto a microbridge that enable the power efficiency heating the device and enhance its sensitivity to gas concentration. This fabrication process (MicraGEM) provided by CMC (Canadian Microelectronics Corporation) and Micralyne Incorporation. Unfortunately, the devices could not be successfully fabricated although our design did not break any design rule. The main reason is that the process provided error minimum size of self-alignment etching holes. However, this design help CMC and Micralyne to identify and redefine the design rules, also push Micralyne to improve the process in the future.