Sensitivity of trapping effect on Si₃N₄ sensing membrane for ion sensitive field effect transistor/reference field effect transistor pair application

In this study, a novel approach for the application of an inorganic ISFET/REFET pair was presented. Single Si₃N₄ layer was directly deposited on n and p type substrate for the sensing membrane of EIS structures. Through the measurement of pH response and C-V hysteresis, the different pH sensitivity was determined by the electron and hole trapping on n-EIS and p-EIS, respectively. The differential pH sensitivity was 22.8 mV/pH, and the linearity is higher than 99%. The drift effect for the single Si ₃N₄ EIS structures could be minimized to around 1 mV/h by this differential arrangement.