LAUSR

Abstract In this work, we report the development of Titanium Nitride (TiN) as a sensing film for Ion-Sensitive Field-Effect Transistor (ISFET)-based pH sensor, which has been deposited using pulsed-DC (Direct Current) magnetron-assisted reactive sputtering process. The material characterization was carried out using various techniques. TiN-gate ISFETs have been fabricated using self-aligned fabrication process by utilizing five levels of lithography steps. The packaging and encapsulation of the sensor has been done by thick film technology and dam-and-fill approach, respectively. The sensor has been characterized and a high sensitivity of nearly 53.98 mV/pH has been obtained. Drift and hysteresis studies were also carried out. The drift rates for different pH buffer solutions 4, 7, 10 are measured to be 0.368 μ A/min, 0.296 μ A/min, 0.237 μ A/min, respectively. A hysteresis value of 0.50 μ A has been obtained for pH cycle pH 7 → pH 10 → pH 7 → pH 4 → pH 7.