Detection of Low Concentration NO2 gas Using Si FET-type Gas Sensor with Localized Micro-heater for Low Power Consumption

Abstract

The sensing characteristics of nitrogen dioxide (NO2) gas in Si FET-type gas sensor using localized micro-heater are investigated. As the sensing material, a 12-nm-thick indium oxide (In2O3) deposited by a radio frequency magnetron sputtering method is used. The NO2 gas sensing characteristics are examined while varying the applied voltage of the micro-heater (V-H) and the concentration of the NO2 gas at room temperature. The fabricated sensor shows excellent performance in detecting low concentration of NO2 gas (25 ppb) and shows that it can improve the sensing characteristics using the pre-bias scheme while 2 V is applied to the micro-heater with 50 % of duty cycle which only consumes similar to 0.84 mW.