A SnO2 ISFET device and manufacturing method thereof. The present
invention
prepares SnO2 as the detection membrane of an ISFET by sol-gel technology
to obtain a SnO2 ISFET. The present invention also measures the current-voltage
curve for different pH and temperatures by a current measuring system. The temperature
parameter of the SnO2 ISFET is calculated according to the relationship
between the current-voltage curve and temperature. In addition, the drift rate
of the SnO2 ISFET for different pH and hysteresis width of the SnO2
ISFET for different pH loop are calculated by a constant voltage/current
circuit and a voltage-time recorder to measure the gate voltage of the SnO2 ISFET.