Pd—SnOxMIS capacitor as a new type of O2gaseous sensor

Device characteristics of a new type of O
2
gaseous sensor are presented. These sensors are fabricated in the MIS configuration Pd-SnO
x
-Si
3
N
4
-SiO
2
-Si-Al with highly resistive SnO
x
as an oxygen adsorptive element. Partial pressures of O
2
below 0.1 torr can be detected at room temperature by these devices. Steady-state and transient behavior are described as a function of O
2
partial pressure and temperature. Adsorption and desorption rates and time constants are determined. Activation energy for O
2
adsorption in SnO
x
is found to be 1.6 K cal/ mole.