用SiO_2气凝胶做隔热层的铁电薄膜红外探测器性能与铁电薄膜层厚度的关系  

FERROELECTRIC FILM THICKNESS DEPENDENCE OF PROPERTIES OF INFRARED DETECTOR WITH AN SiO_2 AEROGEL THERMAL INSULATION LAYER

作　　者：林铁[1] 孙璟兰[1] 孟祥建[1] 马建华[1] 石富文[1] 张晓东[1] 汪琳[1] 陈静[1] 褚君浩[1] 

机构地区：[1]中国科学院上海技术物理研究所红外物理国家重点实验室,上海200083

出　　处：《红外与毫米波学报》2007年第5期329-331,335,共4页Journal of Infrared and Millimeter Waves

基　　金：国家自然科学基金资助项目(60371040);上海市科委基础研究重点项目(03JC14076)

摘　　要：研究了铁电薄膜红外探测器响应率等器件参数随铁电薄膜厚度的变化.器件的隔热层结构采用气凝胶二氧化硅.实验发现器件的热释电系数,吸收率以及热导均随膜厚增加而增加.铁电膜层厚度为240nm的器件,其热导与微桥结构器件的热导相近,都为10-7W/K量级,证明气凝胶二氧化硅做隔热层能够制备出性能优良的热释电红外探测器.随着薄膜厚度增加,热导急剧增大,这是引起器件响应率降低的原因.制备铁电薄膜过程中的多次650°高温退火可能降低了二氧化硅多孔率.The variation of voltage responsivity of infrared detectors and other parameters of the devices with the thicknesses of the ferroelectric film was studied. The thermal insulation layer of the detector was sol-gel derived porous silica. The absorption, pyroelectric coefficient and thermal conductance of the devices were found to increase with the increase of the ferroelectric film thicknesses. The thermal conductance of the devices with 240nm ferroelectric film was about the same order as those devices with microbridge structure, e.g. 10^-7W/K. This result demonstrates that high quality of infrared detector can be made with an aerogel silica thermal insulating layer. The degradation of the voltage responsivity with the increase of film thickness is due to the rapid increase of the thermal conductance. The repeated high temperature annealing processes at 650℃ during the preparation of the fertoelectric film may cause a decrease in the porosity of the silica.

关 键 词：红外探测器 铁电薄膜厚度 二氧化硅气凝胶 

分 类 号：TN362[电子电信—物理电子学]