Pd—SnOxMIS capacitor as a new type of O2gaseous sensor

Device characteristics of a new type of O2gaseous sensor are presented. These sensors are fabricated in the MIS configuration Pd-SnOx-Si3N4-SiO2-Si-Al with highly resistive SnOxas an oxygen adsorptive element. Partial pressures of O2below 0.1 torr can be detected at room temperature by these devices. Steady-state and transient behavior are described as a function of O2partial pressure and temperature. Adsorption and desorption rates and time constants are determined. Activation energy for O2adsorption in SnOxis found to be 1.6 K cal/ mole.