A capacitor utilizing the Pd-SnO_(x)-Si_(3)N_(4)-SiO_(2)-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 conventional solid state gas sensors....
A capacitor utilizing the Pd-SnO_(x)-Si_(3)N_(4)-SiO_(2)-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 conventional solid state gas sensors. Experimental results showed that the oxygen adsorption on the device was reduced by the application of a positive gate bias. The suppression of oxygen ions at the Pd-SnO_(x), intcrfacc by an external positive gate bias allows us to use the Pd-SnO_(x)-Si_(3)N_(4)-SiO_(2)-Si-Al capacitor as an oxygen sensor. This suppression of oxygen is explained by a model demonstrating that the oxygen adsorption on the device could be suppressed by a downward bending of the energy band of the SnO_(x) layer, under a relatively high positive gate bias.