Exploration of Ion Sensitive Field-Effect Transistor With Dielectric Properties

Abstract

Environmental changes and increased virus effects in COVID-19 like the situation is forcing the design and researchers to develop highly sensitive, low power and low cost mean to detect the presence of biomolecules of different shapes, sizes, and their effects on the human being. Ion-sensitive field-effect transistor (IS-FET) is a biological sensor based on the architecture of metal oxide semiconductor field-effect transistor (MOS-FET). The gate terminal is replaced with a hollow space filled by electrolyte solution and reference electrode at the external surface. The biomolecular enzyme in contact with membrane enters in solution induce net DC potential, alter the oxide surface. The alteration of surface puts variation in threshold voltage and maps on the deflection of drain current. ISFET measures the concentration of charged particles (ions) in the solution; variation into ion concentration produces deflection in the drain current. In this work numerical simulation of ISFET is performed with ENBIOS-2D Lab at Nanohub platform with dielectric SiO2, Al2O3, HfO2 with NaCl and KCl in solution. Channel resistance and capacitance with 3-different electric shows a large variation of capacitance, result in threshold voltage i.e. 318.2 mV with SiO2 and 319.2 mV with Al2O3.