AgIn5S8 延伸式閘極離子感測場效電晶體之研究

The Study on Ionic Sensitivity of AgIn5S8 Thin Film for Extended Gate Field Effect Transistor

季彥良(Yan-Liang Ji)

指導教授 ： 陳建瑞

國立清華大學/工學院/材料科學工程學系/碩士(2008年)

摘要

本論文在ITO表面上使用水熱法鍍 AgIn5S8 的硫化膜，應用在延伸式閘極離子感測電晶體 (EGFET)做為離子感測薄膜，針對 pH 值、銅離子、鉛離子，測量其對離子感應的靈敏度。

本論文得知，以水熱法鍍的 AgIn5S8硫化膜對pH的靈敏度可達50.7mV/pH，得到對Cu2+的靈敏度可達34.2mV/p[Cu2+]，得到對Pb2+的靈敏度可達95.9mV/ p[Pb2+]。

本論文將使用四種不同的EGFET作業方式，分別為 N-type MOSFET-EGFET Linear Mode，P-type MOSFET-EGFET Linear Mode，N-type MOSFET-EGFET Saturation Mode，以及N-type MOSFET-EGFET Saturation Mode取得其對應的靈敏度，期望能得知感測薄膜帶正電位與負電位對離子感測的影響，並藉由量測I-V的特性來推斷 AgIn5S8 對離子的感測靈敏度。 同時使用鉑為感測薄膜的EGFET做為一個參考標準。 做為對 pH 值、銅離子、鉛離子感測靈敏度的比較基礎。

關鍵字

延伸式閘極 ； AgIn5S8 ； 離子感測場效電晶體

並列摘要

Recently, extended gate field effect transistor (EGFET) had been studied for pH meter or biosensor. In this study, the differences between EGFETs by NMOS and by PMOS were introduced. And, with the ion-sense membrane, AgIn5S8 thin films coated on ITO glass substrates by hydrothermal method, the ions-sensitivities were extracted by linear mode and by saturation mode in different concentration solutions of pH/p[Cu2+]/p[Pb2+]. The results show the sulfide film is sensitive to these kinds of ions. The ion sensitivities on membrane surface are 50.7mV/pH, 23.9mV/p[Cu2+], and 95.9mV/p[Pb2+] in NMOS-EGFET under applied bias-voltage 2.5V at reference electrode with saturation mode extraction. The membranes were also analyzed by electron spectroscopy for chemical analysis (ESCA), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. The analysis also shows good crystallinity of AgIn5S8 thin film.

並列關鍵字

AgIn5S8 ； EGFET ； ISFET

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