An uncooled microcantilever IR detector based on bulk silicon technique

This paper presents an uncooled microcantilever infrared (IR) detector, of which the focal plane array (FPA) is fabricated based on bulk silicon technique. Compared with conventional cantilever IR detector fabricated with surface micromachining method, the IR absorption efficiency can be improved by 48% due to the selective removal of the substrate silicon with deep reactive ion etching (DRIE) technique at the area where each FPA pixel is located, and hence the noise equivalent temperature difference (NETD) can be decreased by 32%. Human body´s images were captured by the fabricated FPA at room temperature with an optical readout system. The thermo-mechanical sensitivity of the FPA pixel was measured to be 0.12 mu/K and the NETD of the IR detector was 310 mK. The image quality was improved by post image processing technique.