Conventionally photonic crystals (PC) has attracted the interest of many researchers on visible and near infrared optical materials which are applied to enhance the absorption and emission of light. In this paper, we focus on the infrared region which leads the photonic crystal on the sensing area of thermopile to enhance the effect of the infrared thermal absorption. The major challenge for photonic crystals is in fabrication of these structures, with sufficient precision to prevent scattering losses and blurring the crystal properties that can be robustly mass produced. Firstly we propose to combine CMOS technology and post micromachining for fabricating the thermal microsensors with infrared absorption micro-structure of photonic crystal. A highly sensitive infrared detector requires an excellent signal induced by incident infrared radiation to maximize the temperature change. A photonic crystal structure offers significant effects of optical performance, especially for the absorption and emitting of radiation. We develop such a structure of thermopile with a post-process of RIE after the standard 0.35 μm 2P4M CMOS IC process which can be easily and exactly fabricated. Several designs of infrared microsensors are proposed to study influential parameters from the photonic crystal structures. The measurement results show these devices get greatly responses higher than the thermopile without infrared photonic crystal. Our design has been proven to be adequate for commercial batch production.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering