Investigation of thermal type microsensor with infrared photonic crystal

In this paper we have proposed a new complementary metal-oxide-semiconductor (CMOS) thermopile by leading the infrared photonic crystal (IPC) to increase the absorption of infrared radiation. A highly sensitive infrared detector requires an excellent signal induced by incident IR radiation to maximize the temperature change. A photonic crystal structure offers significantly effects of optical performance, especially for the absorption and emitting of radiation. Firstly we develop such a structure of thermopile with high performance by using 0.35μm 2P4M CMOS IC compatible process which can be easily and exactly fabricated. Several designs of infrared microsensors are proposed to study influential parameters from the photonic crystal structure. The measurement results show these devices get greatly responses higher than the thermopile without infrared photonic crystal. To that end, the investigation of field of view for our proposed thermopile is acquired, and the results show no significant difference between the thermopiles with or without PC. Our design is proved to be adequate for commercial batch production.