基于MOSFET漏电流温度特性的室温红外探测器

Uncooled infrared detector based on temperature dependence of drain current of MOSFET

基于MOSFET的漏电流温度特性,提出了一种可与CMOS工艺兼容的新型室温红外探测器。它采用在SOI衬底上实现的MOSFET作为探测红外灵敏元,在MOSFET的钝化层上制作可提高红外吸收率的光学谐振腔,并利用硅微机械加工技术将SOI的隐埋氧化层悬空,形成热绝缘微桥结构。MOSFET在担当探测红外辐射灵敏元的同时,又作为放大处理电路的一部分,简化了电路。分析表明,探测器的探测率可高达109～1010cmHz1/2W-1。

An novel micromachined uncooled infrared detector based on temperature dependence of drain current of MOSFET is proposed. It utilizes a MOSFET fabricated on SOI substrate as thermosensitive element. An IR resonance cavity formed on passivation layer of MOSFET improves IR(8～14μm) absorptivity and a microbridge fabrication using micromachining technique provides a low thermal conductance. The temperature dependence of drain current of MOSFET, IR detection principle and device's structure are presented. The performance of IR detector based on numerical analysis and finite element analysis (FEA) is estimated that the detectivity (D\+*) can reach 10\+9～10\+\{10\}cmHz\+\{1/2\}W\+\{-1\}.