电容式非制冷红外焦平面阵列设计及优化

提出一种基于MEMS工艺弯折双材料悬臂梁结构的电容式非制冷红外焦平面成像阵列（FPA,Focal Plate Array）。并利用软件CoventorWare对器件的物理学特性进行有限元模拟分析。发现FPA的温度响应度和位移响应度与辐射能量呈线性关系;得到热时间常数、位移、温度灵敏度与铝膜与二氧化硅厚度比的关系,并得出当比率为0.5～0.6时位移响应最大,100μm×100μm和50μm×50μm两种尺寸器件的位移灵敏度峰值分别为0.061nm/pW.μm^-2和0.008nm/pW.μm^-2;随着器件尺寸的增大,其探测能力增强,瞬态响应降低;计算了吸收面与探测极板间的吸合附电压,得到100μm×100μm面板的吸附电压为3.625V～3.750V之间,50μm×50μm面板的吸附电压为10.250V～10.375V之间,以及器件尺寸与吸附电压间的关系.

Structure Optimization Design of an Uncooled Infrared Focal Plate Array

An uncooled capacitive infrared FPA（focal plate array） system based on MEMS technology and a folded bi-material cantilever microstructure is presented.Thermal,thermalstructural and electrostatic-structural behaviors were simulated with CoventorWare.It is found that both the temperature response and displacement response increase linearly as the absorbed infrared energy increases.The relations between the thermal time constant and Al to SiO2 thickness ratio,the displacement sensitivity and Al to SiO2 thickness ratio,and the thermal sensitivity and Al to SiO2 thickness ratio were studied.The peak displacement sensitiveties were calculated as 0.061nm/pWoμm-2 and 0.008nm/pWoμm-2 for 100×100μm and 50×50μm plates when thethickness ratio of Al to SiO2 films was 0.5～0.6.Electrostatic-structural pull-in behaviors of the divices were simulated.The pull-in voltages for the 100μm square plate were between 3.625V and 3.750V,and 50μm square plate were between 10.250V and 10.375V.With the increasing of the structure dimensions,the thermal time constant increased,the pull-in voltage decreased,but theirs transient performances became worse.