Self-sensitivity amplifiable dual-gate ion-sensitive field-effect transistor based on a high-k engineered dielectric layer

Abstract

In this study, we propose a self-sensitivity amplifiable pH-sensor platform based on a dual-gate (DG) structure ion-sensitive-field-effect-transistor (ISFET) by applying a high-k engineered dielectric layer. We implement amplification according to the capacitance ratio of top and bottom gate dielectric layers through the capacitive coupling effect of DG structure, which exceeds the Nernst limit of the existing ISFET, and maximizes device sensitivity by extracting the change in current based on a reference voltage. In repeated and continuous pH sensitivity measurements and reliability evaluations under external noise conditions, the proposed sensor platform demonstrated excellent linearity and stability. Because the proposed sensor platform significantly exceeds the Nernst limit and has excellent reliability, it is expected to be a promising technology for use as a biosensor platform for detecting analytes with micro potentials.