Ag metal mid layer based on new sensing multilayers structure extended gate field effect transistor (EG-FET) for pH sensor

This study focus on the effectiveness of ZnO/Ag/ZnO (ZAZ) multilayers films thickness on electrical properties of pH sensor and structural properties such as XRD, AFM, the multilayers structure ZnO/Ag/ZnO deposit on glass substrate by using RF and DC magnetron sputtering system at different thickness (200/100/200) nm, (100/50/100) nm, XRD results indicated that the multilayers have polycrystalline phase for Ag metal. ZnO/Ag/ZnO was tested as EGFET for the first time the effect of multilayers thickness on chemical sensitivity, linearity and hysteresis voltage were demonstrated and found 0.62μA1/2/pH, 99.92%, 5.4 mV for multilayer thickness (200/100/200) nm while 0.25 μA1/2/pH, 97%, 3.2 mV at multilayers thickness (100/50/100) nm respectively.