Simulation of ion sensitive transistors using a SPICE compatible model

The goal of this paper is to present a SPICE compatible electro-chemical model of the ion sensitive field effect transistor (ISFET). The presented approach is not entirely new and constitutes certain improvement of earlier works, e.g. by Grattarola et al. The main novelty of the model consists in the introduction of variable carrier mobility and the application of a more advanced model of the electrolyte double layer. These improvements allowed more accurate simulation of the device operating with different hydrogen ion concentrations and in different temperatures.