多種互補式金氧半場效電晶體製造相容之感測層材料在酸鹼離子感測器之研究

Abstract

本論文係利用互補式金氧半導體(Complementary Metal Oxide Silicon Field Effect Transistor, CMOS) 標準製程完成酸鹼值離子感測場效電晶體(pH-Ion Selective Field Effect Transistor, pH-ISFET)的製作。pH-ISFET與CMOS不同的是將金屬閘以離子感應層(Ion Sensing Layer)、酸鹼緩衝溶液(pH Buffer Solution) 和一外加之參考電極取代，元件的電性隨著離子感應層和溶液的表面接觸性質而改變。本實驗安排多種與CMOS製程相容的材料，如氮化矽(Si3N4)、三氧化二鋁(Al2O3)、二氧化鋯(ZrO2)、二氧化錫(TiO2)以及二氧化鉿(HfO2)等配合不同的通道長寬比以及製程條件來製作離子感應層，利用不同材質的感應層，其化學平衡的機制不同對飄移速率、感應度、反應時間、穩定度等元件特性的影響來尋求最佳特性材料。 在此篇論文中，我們將詳述酸鹼離子感測器的製作流程及量測條件，並且在文末藉由實驗數據來分析各種離子感應層的特性；此外，敘述利用NH3電漿對各種離子感應層作表面處理對pH-ISFET特性的影響及改善。

In this thesis, standard manufacture processes of Complementary Metal Oxide Semiconductor (CMOS) are introduced to fabricate Ion-selective Field Effect Transistors (ISFET). This device is differ from MOSFET on the metal gate of MOSFET was substituted by an ion-sensing layer, pH buffer solution and an additional reference gate. The I-V characteristic curves were altered by the interface reactions of sensing layer and electrolyte solution. In our experiment, we use various CMOS fabrication compatible materials, such as silicon nitride (Si3N4), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), Tinoxide (TiO2) and hafnium dioxide (HfO2), with several width/length channel dimension and different process techniques to produce ISFETs. The materials will cause different characteristics such as drift, sensitivity, response time and stability. In this thesis, we reported the fabrication process flow and measurement condition in detail, and analyzed the characteristics mentioned above.