Ultrasensitive pH Sensor Using the Surface Roughness Modification of Sensing Part Based Extended-Gate Field-Effect Transistor (EGFET)
발표자
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초록
내용
This study aims to develop a high-sensitivity and stable pH sensor by overcoming the passivation issues of conventional ISFET pH sensors. They fabricate an EGFET (extended-gate field-effect transistor) pH sensor, where the sensing part and transistor are separated, eliminating the need for passivation and ensuring stability as the electrolyte solution doesn't directly contact the FET. To enhance sensitivity, they modify the extended-gate surface roughness using wet etching and nanoimprint lithography, increasing the sensing surface-to-volume ratio. The EGFET pH sensor utilizes indium gallium oxide (IGO) as the semiconductor and heavily n++-doped Si wafer as the extended gate, modified with APTES. The fabricated sensor exhibits high sensitivity and low hysteresis in the pH range of 3 to 11, making it suitable for various applications like chemical processes, food manufacturing, and environmental monitoring.