延伸式閘極離子感測場效電晶體穩定度之研究

Study on Stability of Extended Gate Field Effect Transistor

邱嘉政(Chia-Cheng Chiao)

指導教授 ： 熊慎幹

中原大學/工學院/電子工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100095

摘要

本論文之目的係研究延伸式閘極離子感測場效電晶體之穩定度特性，以發展pH-ISFET或生醫感測元件之應用。其主要的研究內容包括感測度、線性度、遲滯、時漂、再現性及長期穩定性。延伸式閘極離子感測場效電晶體乃是將離子感測薄膜從場效電晶體之閘極上分離出來，因此，與傳統的open-gate ISFET架構比較，只有感測膜置於緩衝溶液中，而場效電晶體的部分則不需要置於溶液中，以避免光照射之影響。因分離的離子感測膜有架構簡單、容易製造與封裝等優點，使得低成本的延伸式閘極離子感測場效電晶體是可預期的。
在本實驗中我們探討四種不同架構之延伸式閘極離子感測場效電晶體，包括SnO2/ITO glass、TiN/SiO2/Si、SnO2/Al/Si以及TiN/Al/Si EGFET，其中二氧化錫及氮化鈦感測膜係利用射頻濺鍍法所備製。在論文中，我們除了探討每一種架構之穩定度特性外，並提出遲滯和時漂效應的理論及模型，進而解釋它們的機制。
根據實驗結果顯示，SnO2/ITO glass EGFET的整體特性符合要求，足以發展可拋棄式的氫離子感測元件及生醫感測器之應用。

關鍵字

遲滯 ； 二氧化錫 ； 時漂 ； 延伸式閘極離子感測場效電晶體 ； 穩定度

並列摘要

The objective of this thesis is to study the stability of extended gate field effect transistor (EGFET) for pH-ISFET or biosensor applications. The major research issues include sensitivity, linearity, hysteresis, time drift, reproducibility and long-term stability. The ion sensitive membrane of the EGFET is split from the field effect transistor. Accordingly, compared to the conventional open-gate ISFET structure, only the sensitive membrane stays in the buffer solution, but the portion of the field effect transistor needs not put into the solution and avoid illumination effects. The low cost of EGFET can be expected because the separated ion sensitive membrane has advantages of simple structure, uncomplicated fabrication and encapsulation.
In the experiments, we studied four types of EGFET with different structures that include SnO2/ITO glass, TiN/SiO2/Si, SnO2/Al/Si and TiN/Al/Si EGFET, where SnO2 and TiN films were deposited using R.F. sputtering method. Besides the stability of each structure has been investigated, the theories and models have been also proposed for hysteresis and drift effects to explain their mechanisms.
From the experimental measurements, overall characteristics of the SnO2/ITO glass EGFET present satisfactory performance for disposable H+ sensing and biosensor applications.

並列關鍵字

tin oxide ； hysteresis ； stability ； EGFET ； drift

參考文獻

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