Abstract
The sensitivity of conventional ion-sensitive field-effect transistors (ISFETs) is limited to 59 mV/pH, which is the maximum value in electrochemical potential according to the Nernst equation. Here, the silicon-on-insulator (SOI) based dual-gate (DG) ISFETs with SiO2/Al2O3 (OA) using solution based process was evaluated to obtain higher pH sensitivity. The device exhibited a significantly enhanced pH sensitivity of 407.3 mV/pH for the DG operation by capacitive coupling between top and bottom gate oxide. Therefore, the SOI-based ISFETs using solution process and the DG monitoring method are very promising to biological sensors application in terms of high performance and large process area.