抄録
This paper describes the design and fabrication of a microlens for the sensitivity improvement of uncooled infrared array sensors. We improved the sensitivity by collecting infrared rays to detectors. The microlens is made of silicon, which is a typical substrate for MEMS technology. We fabricated it by photolithography technology using a gray scale mask and an etch-back process by selectivity-controlled dry etching. This process enables us to fabricate a 43-µm-high silicon microlens from only a 2- to 3-µm-high photoresist structure. To confirm the usefulness of the microlens, we developed a small infrared array sensor with microlens. The results show that the sensitivity improvement with the microlens is 4.2 times. Microlens is one promising technology for sensitivity improvement.
