紅外線感測器依感測原理主要分為量子型(Quantum)與熱型(Thermal)。早期使用光電原理為感測機制的量子型紅外線感測器，雖然有高靈敏度的優點，但因為價格昂貴且需額外的冷卻系統以維持系統運作正常，主要應用在軍事領域或航太的夜間辨識，且此類感測器亦有使用壽命不長的問題。
　　如今因為微機電(MEMS, Micro-Electro-Mechanical System)技術的發展以及CMOS製程技術的成熟，室溫下使用TCR(Temperature Coefficient of Resistance)為感測機制且與CMOS製程相容的熱型紅外線感測器，結合CMOS/MEMS的優點，容易達到低價化且大量生產的目標，應用到範圍更寬廣的民生用途上，比如說居家保全或提升汽車夜間駕駛的安全性。
　　由於紅外線感測器對製程有很高的相依性，目前國內發表的論文中，專注在前段材料製備的研究往往使用簡單的後段量測電路或以外接的方式處理，導致訊號容易因種種雜訊干擾而表現不佳；而專注在後段的讀取電路設計者，往往以簡單的二極體或BJT來模擬感測元件的小訊號變化，忽略了整體製程的考量，尤其是後段蝕刻條件的限制。
　　本實作使用財團法人國家晶片系統設計中心(National Chip Implementation Center)委託台積電代工之0.35μm 2P4M(2Poly/4Metal Layer) CMOS/MEMS 製程，並在成功大學微奈米中心完成以電化學蝕刻為主之後段製程。在感測器系統設計上，我們採用Closed-Loop形式的電熱式(Electro-Thermal)負迴授(Negative Feedback)架構，利用負迴授抑制感測元件主體溫度，使溫度變化反應在電壓變化上，利用電路特性來提升感測器的靈敏度。此種電壓變化與一般利用TCR(Temperature Coefficient of Resistance)來改變電阻值不同，操作在較低的工作電流下即能達到較高的靈敏度。本實作完成了紅外線感測器的單位組件，實際將感測元件與讀取電路的前端整合在一起，我們希望將來在這個基礎上朝陣列化發展，最後出便宜且靈敏度高的紅外線感測器，使其能夠應用在居家保全及夜間辨識等一般商用領域。
　　我們亦開發了一套實作流程，將CIC切割後送回之3mm x 3mm大小的晶片，導入電化學單面蝕刻製程，最後再進行訊號量測。此製程亦適用於大部分切割成小塊晶片後欲進行單面濕蝕刻之CMOS/MEMS設計。文中將討論實作時遇到的困難，並以此來檢討修改原始的設計。此實作上的心得，當會對未來的CMOS/MEMS申請者有所幫助。

　　Infrared Sensors are mainly sorted in Quantum type and Thermal type. The principle of quantum type infrared sensor is “photovoltaic effect”, a process which the energy of the photon is transferred to an electron. Quantum type infrared sensors have much higher sensitivity than thermal type’s but need other cooling system to keep normal operation. Life time and price are other two major faults and made them developed most for military purpose.
　　Thermal type infrared sensors, which make use of TCR (Temperature Coefficient of Resistance), have grown up in recent years by the maturation of CMOS process and MEMS (Micro-Electro-Mechanical System) technology. They have two advantages over quantum type sensors, CMOS compatible and room temperature operation environment, the former make them cheap and the later make them commercial-attracted, though their sensitivity is much lower than their opponents.
　　However, the thermal type infrared sensors are highly process-sensitive. There are two main streams in this region; one is focus on sensing material which has simple readout circuits instead, the other is focus on readout circuits and using a simple BJT/Diode to simulate resistance/current variation. They both do not have a circumspect consideration in manufacturing process, which often conflict with each other.
　　Our application was reviewed by National Chip Implementation Center and manufactured thorough TSMC 0.35μm 2P4M CMOS/MEMS process. The post TMAH etching process was implemented in National Cheng Kung University’s Center of Micro/NANO Technology Research.
　　In system design, we adopt a Closed-Loop scheme which construct from electro-thermal balance, forming a negative feedback system, and keep the temperature of unit cell stable. We integrated the sensing unit with a front part of readout circuits in a unit cell, and probe their performance before and after TMAH etching.
　　Several experimental procedures which suit for a 3mm x 3mm size chip are also showed. We make possible that a cut chip could run through whole TMAH electrochemical etching process and still be able to get probed. These experiences may be helpful to students who would apply CMOS/MEMS process.

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