Fabrication, Characterization, and Modeling of an Aluminum Oxide-Gate Ion-Sensitive Field-Effect Transistor-Based pH Sensor.

The ion-sensitive field-effect transistor (ISFET) is a popular technology utilized for pH sensing applications. In this work, we have presented the fabrication, characterization, and electrochemical modeling of an aluminum oxide (AlO)-gate ISFET-based pH sensor. The sensor is fabricated using well-established metal-oxide-semiconductor (MOS) unit processes with five steps of photolithography, and the sensing film is patterned using the lift-off process.