Novel flash ion sensitive field effect transistor for chemical sensor applications

Electrolyte-insulator-semiconductor (EIS) devices with programmable Sm₂O₃/Si₃N₄/SiO₂ and HfO₂/gadolinium oxide nanocrystals (Gd₂O₃-NCs)/SiO₂ structures are demonstrated for pH detection. The proposed programmable EIS sensors with multiple sensing membranes exhibit a high pH sensitivity (larger than the ideal Nernst response, 59.16 mV/pH at 25 °C) owing to the hydrogen ions attraction by electrons trapped within the embedded trapping layers (Si₃N₄ and Gd₂O₃-NCs) after programming. When compared with the conventional EIS devices, the programmable EIS sensors with programming provide the possibility for the small pH fluctuation detection and can be used in future pH sensor applications owing to its high pH sensing response.