以原子尺度模擬探討生物分子吸附於矽奈米線的能帶變化與導電機制

Band structure and conductivity mechanism of bio-molecules binding on silicon nanowire

林正偉(Cheng-Wei Lin)

指導教授 ： 陳俊杉

國立臺灣大學/工學院/土木工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.01143

摘要

矽奈米線場效應電晶體作為生物感測器具有高靈敏度、即時偵測、高重現性、無標記檢測和運用現今發展成熟的微機電製程等優點，近年來越來越受到重視。如果能夠說明場效應電晶體的閘極效果，和矽奈米線鍵結分子的行為，將能夠讓我們更了解生物感測器背後的機制。

本研究使用密度泛函理論，以ATK這套軟體計算閘極的影響和鍵結分子的行為，使用三種模型：氫鈍化矽(100)奈米線、氫鈍化矽(100)奈米線施加閘極電壓和氫鈍化矽(100)奈米線鍵結分子，分別分析其傳送頻譜、態密度、傳送比例和特徵態等進行比較。

模擬結果發現氫鈍化矽(100)奈米線做為一完整結構，表現在傳送頻譜上是一階梯狀結構，代表在特定能量點提供的通道可以被電子完全佔滿，特徵態分析是一連續性結構；而氫鈍化矽(100)奈米線施加閘極電壓和氫鈍化矽(100)奈米線鍵結分子，兩者在傳送頻譜上皆表現出係數值的降低，特徵態分析看到中斷的等值面，呈現出閘極電壓和鍵結分子具有等效關係。

關鍵字

生物感測器 ； 場效應電晶體 ； 矽奈米線 ； 鍵結分子 ； 閘極電壓

並列摘要

Silicon nanowire ( SiNW ) field effect transistors ( FET ) are attracting much interest for their high sensitivity, real-time detection, reproducibility, label-free and using micro-electro-mechanical process. It is imperative for us to reveal the gate effect of FET and the behavior of SiNW binding molecules by simulation, which could help us realize the microscopic mechanisms.

The research bases on density functional theory packed in ATK software. Analyse three models: H-passivated Si(100) nanowire, Si(100) nanowire experienced gate voltage effect and Si(100) nanowire binding molecules by transmission spectrum, density of state, transmission percentages and eigenstates individually.

Simulation results show that H-passivated Si(100) nanowire as a perfect structure which can be observed by step-wise curve in transmission spectrum. It means that the channels at specific energy can be occupied 100% by electrons, and it is continuous in eigenstate structure; however, in H-passivated Si(100) nanowire with gate voltage effect and H-passivated Si(100) binding R-APTES molecules, both of them display reduction of coefficient in transmission spectrum and discontinuity in eigenstate which show that there exists equivalent relationship between gate voltage effect and binding molecules.

並列關鍵字

biosensor ； field effect transistor ； silicon nanowire ； binding molecules ； gate voltage

參考文獻

[1] Yi Cui, Qingqiao Wei, Hongkun Park, and Charles M. Lieber, Nanowire Nanosensors for Highly Sensitive and Selective Detection of Biological and Chemical Species, Science, 293, 5533, 1289-1292 (2001)

[2] Jong-in Hahm and Charles M. Lieber, Direct Ultrasensitive Electrical Detection of DNA and DNA Sequence Variations Using Nanowire Nanosensors, Nano Letters, 4, 1, 51-54 (2004)

[3] F. Patolsky and C.M. Lieber, Nanowire nanosensors, Materials Today, 8, 20-28 (2005)

[4] Dorothee Grieshaber, Robert MacKenzie, Janos Vörös and Erik Reimhult, Electrochemical Biosensors - Sensor Principles and Architectures, Sensors 8(3), 1400-1458 (2008)

[5] M. C. Lin, C. J. Chu, L. C. Tsai, H. Y. Lin, C. S. Wu, Y. P. Wu,Y. N. Wu, D. B. Shieh, Y. W. Su, and C. D. Chen, Control and Detection of Organosilane Polarization on Nanowire Field-Effect Transistors, Nano Letters, 7, 12, 3656-3661, (2007)