This note reports on the development of a novel cantilever-based focal plane array (FPA) for uncooled infrared (IR) imaging. The FPA of 160 × 120 pixels consisted of a 1 µm thick low stress SiN x structure layer, a thin gold reflection layer and a thick gold bimaterial layer. A bulk silicon process that includes silicon-glass anodic bonding and deep reactive ion etching techniques was developed selectively to remove the substrate silicon and form silicon frames for every FPA pixel. The thermomechanical sensitivity of the cantilever pixel was measured as 0.11 µm K −1 , the noise-equivalent temperature difference of the FPA was theoretically estimated to be below 60 mK and the response time was calculated to be 15 ms. An optical readout system was used to measure deflections of all cantilevers in the FPA simultaneously, and thermal images of the human body were captured in good time. One of the unique advantages of this honeycomb-like FPA is the selective removal of the silicon substrate, which could increase the IR absorption efficiency by 48% compared with that fabricated by a traditional surface sacrificial layer process.

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An IR imaging system based on a microelectromechanical system (MEMS) microcantilever is uncooled, low-cost, and more reliable than traditional systems. However, it is difficult to avoid unwanted shape distortions in fabrication, which can degrade image quality in many ways, so we use holography to compensate for these shape distortions in an optical readout focal plane array (FPA) IR imaging system. The experiment shows that it is a feasible way to improve system performance, especially when it is too difficult to perfect the techniques of an FPA fabrication.