ELECTRIC-FIELD-INDUCED ADSORPTION DESORPTION OF OXYGEN ON A PD-SNOX-SI3N4-SIO2-SI-AL CAPACITOR/

A capacitor utilizing the Pd-SnOx-Si3N4-SiO2-Si-Al structure to detect oxygen was developed. The capacitor is able to detect O-2 in a vacuum environment at a much lower operating temperature than the convention al solid state gas sensors. Experimental results showed that the oxyge n adsorption on the device was reduced by the application of a positiv e gate bias. The suppression of oxygen ions at the Pd-SnOx interface b y an external positive gate bias allows us to use the Pd-SnOx-Si3N4-Si O2-Si-Al capacitor as an oxygen sensor. This suppression of oxygen is explained by a model demonstrating that the oxygen adsorption on the d evice could be suppressed by a downward bending of the energy band of the SnOx layer, under a relatively high positive gate bias.