Performance Enhancement of ISFETs in Standard CMOS Technology Using Anti-Reflection Coating as Ion-Sensitive Layer and FLOTOX Tunnel Devices

Abstract - We present the characterization results of ion-sensitive field-effect transistors (ISFETs) fabricated in Standard CMOS technology with implemented tunnel structures for bidirectional electron tunneling in terms of sensitivity, drift, signal resolution and trapped charge compensation. The mean pH sensitivity, drift and signal resolution of 44.7 mV/pH, 1.8 mV/h and 0.002 pH, respectively are the best achieved performance parameters of ISFETs with an ion-sensitive Si3N4 layer fabricated in standard CMOS process without customized modifications reported so far. This enables their use as biosensors in applications with high sensor demands such as in molecular diagnostics and DNA sequencing.