Fabrication and characterisation of Al gate n‐metal–oxide–semiconductor field‐effect transistor, on‐chip fabricated with silicon nitride ion‐sensitive field‐effect transistor.

In the present study, temperature drift analysis of metal–oxide–semiconductor field‐effect transistor (MOSFET) is carried out using silicon nitride/SiO2 as dielectric film. An n‐channel depletion‐mode MOSFET was fabricated with silicon nitride ion‐sensitive field‐effect transistor (ISFET) on the same wafer. The study presents the fabrication, simulation and characterisation of MOSFET. The gate of the ISFET is stacked with silicon nitride/SiO2 sensing membrane that was deposited using low pressure chemical vapour deposition. Output and transfer characteristics of on‐chip fabricated Al gate MOSFET were obtained in order to study the fabricated ISFET behaviour to be used as pH sensor. Silicon nitride is preferred over SiO2 sensing film/dielectric (in case of MOSFET) which has better sensitivity and low drift. Process and device simulations were performed using Silvaco® TCAD tool. [ABSTRACT FROM AUTHOR]