多晶矽奈米場效應電晶體

Abstract

在醫學的檢測上開始以分子標誌診斷方式判斷，治療方式也開始對引發疾病的分子做特定的治療，相當需要具有高效率且可以快速檢測分子的工具，而現今的技術平台提供了一個可信賴、快速、低成本、及多通道檢測生物標誌的診斷方式，可以早點發現疾病，對於癌症早期發現所做治療的成功率，一般將會最高。 因為微影技術的進步，元件尺度縮小至奈米等級，過去已有人提出用奈米線來製作生物分子的感測器如蛋白質、DNA、離子...等等的感測。過去的研究當中，用來作為生物分子感測器的奈米線，不是採用化學氣相沉積法(chemical vapor deposition,CVD)就是使用單晶矽-氧化矽-單晶矽晶圓(silicon on insulator,SOI)的方式達成，前者因為在製作上電極的安排會遭受到製程上的困難，而後者則是成本較一般標準半導體製程來得高出許多。 因此在論文中我們提出了一個新的方式解決上述的問題。我們選擇製作一個多晶矽奈米場效應電晶體來感測pH值，在論文的第一部分我們首先製做使用下閘極結構(bottom gate)的電晶體(Field Effect Transistor,FET)，在量測pH值時，將元件蓋上光阻，使用曝光機將通道露出 (biochemical sensor)，此結構不僅沒有電極安排上的困難，且可以現今的半導體製程實現，未來希望可以感測生物分子。

Medicine progresses toward Diagnostics based on molecular marker, and highly specific therapies aimed at molecular targets, the necessity for high-throughput methods for the detection of biomolecule increases. Technology platform that provide diagnostics which is reliable, rapid, quantitative, low-cost and muti-channel identification of biomarkers. Disease could be found early. Early detection of cancer are treated with the greatest possibility of success. Due to lithography technology’s progressing, device’s dimension has decreased to nanometer. Recently nanowire has been proposed to detect proteins, DNA, ions…etc. Nanowire used to function as biosensor had been showed, which was made either by CVD(chemical vapor deposition) or by using SOI(silicon on insulator). The former has trouble in electrode arranging, and the latter is suffer from higher cost than standard semiconductor process. In thesis, we announced a new way to solve the problems. We fabricate polysilicon nanowire field effect transistor to sense pH value. In the first part of thesis, we made FET with bottom gate. And When measuring pH value, device layer is cover by photoresist. Channel is open by aligner. The structure not only doesn't have problem in arranging electrode but also could be made by standard semiconductor process. In the future, it will be used to detect biomolecules