Modeling of the pH-ISFET thermal drift

Abstract

The temperature effect on pH-ISFET response has been modeled by taking into account the dependence with temperature of the dissociation constants Ka, Kb at the SiO2/Si3N4 electrolyte/insulator interface. The relationship of Ka, Kb versus the temperature is implemented in the development model based in the site-binding model combined with the level 3 of PSPICE model of MOSFET. The model parameters were extracted using genetic algorithm and the simulations results using these values showed a good fit between modeling and experimental data on a large temperature range.