低成本可攜式多晶矽奈米線場效電晶體 生物感測晶片量測系統之開發

Abstract

以單晶矽奈米線場效電晶體為基礎的生物感測晶片具有生物體容易標定、高靈敏度、具專一選擇性、即時回應、無標記檢測、極少量樣品需求以及快速篩選的優點，日益成為生化感測、醫學檢驗、新藥開發平台應用方面一個重要的研發產品。但是單晶矽的成本高，以致難以普及。而多晶矽奈米線場效電晶體則成本低，於是五年來遂成為商品化的生化分子感測元件的發展重點。 傳統上，矽奈米線場效電晶體生物感測晶片在偵測樣品時，其檢測平台須置於龐大的真空腔與鐵櫃內，以降低水氣與電磁波雜訊的干擾。此外，其奈安培至微安培數量級的汲極電流Id訊號隨閘極電壓Vg的變化關係，多倚賴昂貴的商用量測系統量測。結果，龐大的體積與昂貴的價格，反而成為生物感測晶片商品化的新障礙。 因此，本論文的目標是自製一套簡化版的量測儀器以降低成本，並便於攜帶。同時，大幅縮小多晶矽奈米線場效電晶體生物感測晶片的體積，封裝成如同積體電路IC一樣，具有成本低、體積小、操作易、與隨用即拋等優點。 結果，我們以約二十萬元製作的量測儀器，成功取代價值兩百多萬元的商用量測儀器。而且，生物感測晶片的封裝十分簡易，封裝後體積僅一塊橡皮擦大小，可直接插在簡化版的量測儀器上使用，完全不再須要龐大的檢測平台。最後，藉由Id-Vg電性曲線的量測，我們這套自製的簡易量測儀器與多晶矽奈米線場效電晶體生物感測晶片模組，可分辨不同pH值磷酸鹽水溶液的樣品。

Mono-crystalline silicon nanowire field effect transistor biosensor chip has become an important key to biochemical sensing, and can be used in new drug development. Its advantages include receptor binding, high sensitivity, specific selectivity, immediate response, label free, less sample requirements and rapid screening of excellent features. Mono-crystalline silicon is too expensive to be used widely. The poly-silicon nanowire field effect transistors are low-cost and commercially available, so last five years they have become important development projects in the biochemical molecular sensing field. Traditionally, the detection platform must be placed in a vacuum chamber with a large metal cargo in order to reduce interference of moisture and electromagnetic noise when detecting samples. In addition, to measure drain current Id with gate voltage Vg signal changes usually rely on expensive commercial measurement system. Because of large volume and high prices, these become a new barrier of development and commercialization for silicon nanowire field effect transistors. Therefore, the goal of this thesis is to make a simplified and portable measuring instrument module in order to reduce costs. At the same time, significantly reduce the polysilicon nanowire field effect transistor biosensor chip size, packaged into the same as integrated circuits IC, with low cost, small size, easy operation. Our homemade measuring instrument module about two hundred thousand NT dollars, can replace the commercial measurement system about two million NT dollars. Moreover, biosensor chip is very simple, the encapsulated volume is like an eraser size, can be directly inserted in the simplified measurement system without large detection platform. Finally, using our homemade measuring instrument module with polysilicon nanowire field effect transistor biosensor chip, we can distinguish different pH samples by Id-Vg curve of electrical measurements.