Application of FET Sensor Technologies

A comprehensive update of the application of field effect transistor (FET)-based variety sensors for temperature, pH, and for gas detection is presented with a focus on the fabrication methodologies and novel materials. The introduction of modern temperature sensors based on CMOS has made a highly energy-efficient and compact design possible for integration into IoT and wearable systems. Silicon carbide (SiC) is a wide bandgap material with excellent thermal stability, suitable for high temperature and power electronics environments with compact device architectures. Due to their better chemical sensitivity on the one hand, and long-term stability and low drift on the other hand, extended gate and ion-sensitive FETs based on materials such as ZnO, RuOx, and Al₂O₃ are more suitable for biomedical and environmental monitoring in the pH sensing area. Decoupling of sensing from transistor has clear advantages of flexible design and simpler integration, as in EGFET. Sensors that made great use of the thin films of oxide metal, as well as the tunnelling-based FET structure, such as TFETs and VTFETs, have been devised to achieve high sensitivity and selectivity at ultralow voltages. In addition, the integration of simulation tools and modelling enables the conduct of more precise performance tuning and the prediction of sensor behaviour. Combined, these developments illustrate the power of FET-based sensors in formulating low-power and multipurpose sensing products for next-generation applications.