A New Structure of Cantilever-Based Infrared Focal-Plane Array

This paper presents the design, fabrication and analysis of an infrared focal-plane array (FPA) consisting of bi-material cantilevers. The bi-material cantilevers are made of silicon nitride (SiNx) and aluminum (Al), and which will bend as the temperature changes due to the difference of the two materials in thermal expansion coefficients. In order to enhance the infrared (IR) absorption efficiency of the FPA, deep reactive ion etching (DRIE) technique was introduced to remove the backside Si of the structures. Therefore the IR light can reach the FPA directly. The thermomechanical sensitivity for the finished FPA is measured to be 0.134 μm/K by profile meter, and the noise-equivalent temperature difference (NETD) of the system was estimated to be 18mK.