Multi-finger gate ISFET (Mf-ISFET) for pH sensor application

Study on Ion Sensitive Field Effect Transistor (ISFET) based on multi-finger gate design is presented. Mf-ISFET was fabricated by using commercial submicron 1.0 mum CMOS technology and deposited with PECVD Si 3 N 4 as a sensing membrane. The electrical data such as IdVd and IdVg of ISFET are measured to identify the behaviours of ISFET. Furthermore, the evaluation test on ISFET performance such as transient analysis and hysteresis is also done and discussed in this paper. Based on experimental result gained, better performance of ISFET can be archived by ldquoconditioningrdquo the ISFET before applying it as a sensor.