Impact of postdeposition annealing on the sensing and impedance characteristics of TbY_{: X}O_y electrolyte-insulator-semiconductor pH sensors

In this investigation, we explored the impact of postdeposition annealing (PDA) on the sensing and impedance characteristics of TbY_xO_y sensing films deposited on Si(100) substrates through reactive cosputtering for electrolyte-insulator-semiconductor (EIS) pH sensors. The TbY_xO_y EIS sensor annealed at 800 °C exhibited the best sensing characteristics (pH sensitivity, hysteresis voltage, and drift rate). In addition, the effect of PDA treatment on the impedance properties of TbY_xO_y EIS sensors was studied using the capacitance-voltage method. The resistance and capacitance of TbY_xO_y sensing films were determined using different frequency ranges in accumulation, depletion, and inversion regions. In our impedance spectroscopy analysis, the semicircle diameter of the TbY_xO_y EIS sensor became smaller, due to a gradual decrease in the bulk resistance of the device, as the PDA temperature was increased.