元件製程對於多晶矽奈米線場效電晶體水測電性影響之分析

Abstract

多晶矽奈米線場效電晶體生物感測器使用電訊號偵測生物分子具有極高靈敏度、即時偵測及無需標記物之優點。儘管矽奈米線場效電晶體具有以上的優勢，但是典型測試在水溶液電性變化影響之研究卻極少探討。在這裡，我們研究如何製作多晶矽奈米線場效電晶體以改善元件於水溶液環境下量測之電訊號穩定性。多晶矽奈米線場效電晶體於背閘極上，我們個別堆層二氧化矽及氮化矽兩種材料絕緣層及分析些兩種元件之電性號變化。同時使用新穎微流道保持水中環境並討論不同長度、不同條數之矽奈米線場效電晶體之水中電性測試。發現兩種材料作為絕緣層都具有極高的靈敏度與於水中測試之穩定度。最後，由於奈米線為矽材質，因此我們使用未固定化及固定化後之奈米線氮化矽作絕緣層元件測量不同pH值之PBS之關係。

Biosensors based on silicon nanowires promise real-time, highly sensitive and label-free electrical detection of biomolecules. Despite the tremendous potential and promising experimental results, the fundamental mechanisms of electrical sensing in aqueous environment remain poorly understood. In this work, we investigated how the fabrication process can help to improve the reliability of poly-Si nanowire filed-effect transistor (NWFET) in aqueous solution. Dielectric layers, silicon oxide or nitride, was prepared on the top of back gate in poly-Si NWFET and their effects on device characteristics were determined. The poly-Si NWFET was also prepared with variations of the number and length of the nanowires. The results indicated that either nitride or oxide dielectric layers as insulator improved the stability of poly-Si NWFET devices in aqueous solution. Finally, the pH effect on the electric properties of poly-Si NWFET was further investigated using unmodified and APTES modified device is nitride dielectric layer.