基於奈米蕭特基二極體與快速熱退火處理建構之侷域式表面電漿子共振生物感測器

Localized Surface Plasmon Resonance Biosensor Based On Schottky Nanodiode and Rapid Thermal Annealing

廖勇翔(Yung-Hsiang Liao)

指導教授 ： 林啟萬

國立臺灣大學/工學院/醫學工程學研究所/碩士(2022年)

https://doi.org/10.6342/NTU202200069

摘要

近年來，針對高風險族群推行阿茲海默症、帕金森氏症等神經退化性疾病早期篩檢已納入政府長照政策，對於高敏感度、易於操作同時兼具低成本的生物醫學感測系統的需求呼之欲出，且越來越多的突發傳染性疾病，例如當下肆虐全球的新型冠狀病毒肺炎等，令社會醫療資源吃緊、負擔日益嚴重，也對感生物感測技術提出高通量、高效率的要求。傳統的光學式SPR生物感測器具有即時、免標記、高靈敏度、高特異性等優點，卻也因其光學系統架構精密、複雜，體積龐大又昂貴使得應用場域大大受限。
本研究基於表面電漿共振激發產生熱載流子的理論，設計及製造具有Au-TiO2蕭特基勢壘（能障）結構的生物感測元件，用於激發表面電漿共振，同時有效分離、提取與表面電漿共振相關之熱電子。在原理和元件設計上，本研究吸納實驗室先前經驗和國內外類似研究成果，採用金屬奈米孔洞結構作為關鍵結構，以激發侷限式表面電漿共振，以期提升訊雜比，提升感測器性能指標，進一步討論在表面電漿共振生物感測器應用中，以電訊號量測取代傳統基於影像的光訊號量測的可行性，從而達到簡化機構、降低成本的目標。本研究以微影、真空鍍膜、快速熱退火等奈米微機電技術完成所設計之感測元件的製程，使用專門製作的測試系統，對元件進行電學、光學特性及感測性能分析；此外，我們也借助AFM等方法評估製程品質。
實驗結果顯示，感測器能透過光電流的大小成功地辨別出不同的實驗樣品，且當折射率增加時，相對應的光電流會降低，兩者之間存在一線性關係，且估算出的靈敏度約為-21.183pA/RIU；此外，相較於前人研究的結果，本研究在訊雜比方面亦有顯著的提升改進，經過計算從約-3.5至4.4 dB。本研究針對先前提出欲改善的問題皆有很好的完成，但仍有些問題能被加以改進，因而也在後續章節對此提供未來可能的改善方向。

關鍵字

生物感測器 ； 侷域式表面電漿子共振效應 ； 蕭特基二極體 ； 快速熱退火處理

並列摘要

In recent years, early-stage detection for neurodegenerative diseases, such as Alzheimer's disease and Parkinson’s disease, has been included in the government’s long-term care policy for high-risk groups. Thus, the demand for low-cost biomedical sensing system with high sensitivity and simple operation increased. Furthermore, more and more sudden diseases, such as recent pandemic COVID-19, caused the deficiency of medical resources and became the burden to society, and made the requirement for high throughput and high efficiency higher. The conventional optical SPR biosensor possessed the advantages of real time, free label, high sensitivity and specificity, etc. However, its application field was greatly limited by the complex optical system structure, bulky equipment and its price.
Based on the principle of hot-carrier generation by the excitation of SPR, we designed and fabricated the biosensing chips with Au-TiO2 Schottky barrier structure in order to excite SPR and simultaneously separate and extract hot electrons corresponding to surface plasmon resonance. In the aspect of principles and components design, we assimilated many experiences from previous studies in our lab and domestic and overseas researches. Applying metal nanohole structure played a key role structure in the excitation of LSPR to enhance signal-to-noise ratio and improve sensor performance. Furthermore, further discussions focused on the feasibility of replacing conventional optical signal measurement based on images with electrical signal measurement in the SPR biosensor application. Thus, simplifying structure and costs reduction would be achieved. With the help of MEMS fabrication technique, such as lithography, vacuum deposition and rapid thermal annealing, we accomplished the fabrication of sensing chips and utilized specialized test system to conduct electrical and optical characterization and sensing performance analysis. Besides, AFM images assisted us with the evaluation of fabrication quality.
Experimental results revealed that the sensor could recognize samples through photocurrent measurement successfully. As the refractive index increased, the corresponding photocurrent decreased. Linearity relation existed between the refractive index and the photocurrent, while the sensitivity is -21.183pA/RIU. Furthermore, compared to previous studies, it was also a great improvement in SNR from -3.5 to 4.4 dB. We improved some problems faced in previous studies in this study, but still some of them could become better. Thus, subsequent chapter will provide some possible solution for it.

並列關鍵字

Biosensor ； Localized Surface Plasmon Resonance effect ； Schottky diode ； Rapid Thermal Annealing

參考文獻

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