Optimized Design of High Sensitivity Micromechanical Photon Detectors

With the rapid development of micro-electro-mechanical system (MEMS) technology, uncooled micromechanical infrared detectors become available and attract more and more attention. This paper first deducts the theory of bilayer cantilever with different stress in each layer, and then applies it to the design of micromechanical photon detectors. This theory is somewhat different from the theory in many literatures because it is based on not surface stress but layer stress. With this theory, optimized design of micromechanical photon detectors can be performed, which includes both material choice and geometry determination. As an example, a high sensitivity silicon-based micromechanical photon detector is designed, which reaches a sensitivity of 47 times larger than conventional designs