Extended-Gate ISFETs Based on Sputtered Amorphous Oxides

We present the results obtained with an extended-gate ISFET totally based on amorphous oxides (GIZO as the semiconductor, Ta
₂
O
₅
:SiO
₂
as the dielectric and Ta
₂
O
₅
as the sensitive layer). A full characterization of the device was performed with constant ionic strength pH buffer solutions, revealing a sensitivity of 40 mV/pH with small hysteresis, and good linearity in the pH 4-pH 10 range buffer solutions. These results clearly show that it is possible to produce room-temperature disposable and low cost bio-sensors.