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[摘要]：In order to develop a pH sensor having a good pH-sensing characteristic, electrolyte-insulator-semiconductor capacitors using a high-k Pr2O3 thin film as the sensing membrane were fabricated on silicon substrates by reactive radio frequency sputtering. The structural and morphological features of these films with annealing at various temperatures were studied by X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy. The Pr2O3 sensing film after annealing at 900 degrees C is suggested to the increase in the interfacial SiO2 and silicate formation, and the high surface roughness. Therefore, a physical vapor deposition Pr2O3 film is adopted as a new pH-sensing layer. The result produces a pH response of 52.9 mV/pH (pH = 2-12), a hysteresis voltage of 17.5 mV (pH = 7 -> 4 -> 7 -> 10 -> 7), and a drift rate of 2.15 mV/h (pH = 7 buffer solution). |
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