本研究係利用射頻濺鍍（R. F. Sputtering）系統備製氧化銦錫（Indium Tin Oxide, ITO）薄膜於矽（Si）及二氧化矽/矽（SiO2/Si）基板，以形成ITO/Si及ITO/SiO2/Si感測結構，並結合金屬－氧化物－半導體場效電晶體（Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET）以形成氧化銦錫酸鹼離子延伸式閘極場效電晶體（Extended-Gate Field-Effect Transistor, EGFET）。之後，將感測元件置於不同酸鹼溶液中（pH=2,4, 6,8,10,12），藉由半導體參數分析儀（Keithley 4200）測量感測元件之電流－電壓（I-V）特性曲線，以探討氧化銦錫透明導電薄膜對於酸鹼離子的感測特性。實驗結果顯示氧化銦錫薄膜備製於矽及二氧化矽基板之感測度分別為41.43 mV/pH與43.04 mV/pH，其線性度佳可應用於檢測酸鹼離子。

In this study, the indium tin oxide (ITO) thin film was deposited on the Si and SiO2/Si substrates by radio frequency sputtering system. The ITO/Si and ITO/SiO2/Si sensing structures were connected with the Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs). And the ITO pH Extended-Gate Field-Effect Transistors (EGFETs) were finished. Afterwards, the Semiconductor Parameter Analysis Measurement (Keithley 4200) was utilized to measure the current-voltage (I-V) characteristics curves. And the sensing properties of the ITO pH EGFETs were obtained in the pH=2, 4, 6, 8, 10, 12 buffer solutions, respectively. According to the experimental results, the pH sensitivity of the ITO/Si is 41.43 mV/pH and the pH sensitivity of the ITO/SiO2/Si is 43.04 mV/pH, respectively. In addition, the pH responses are very linear, so the ITO EGFET can apply to pH sensor applications.