The purpose of this paper is to report on metal‐oxide‐semiconductor (MOS) capacitor‐based O2 sensors with different catalytic metal electrode (Al or Pd), deposited on both smooth and porous surface (pore diameter ranging from 2.76 to 71.6 μm) of ZrO2 thin film.
The ZrO2 thin film has been prepared by RF sputtering and DC magnetron sputtering process followed by thermal oxidation process, whereas the electrodes were deposited on thin film by thermal evaporation. The sensors are exposed to O2 gas ambient at room temperature and the O2 sensing performance has been examined by surface characterizations and on‐line sensing electrical characterizations.
MOS capacitor O2 sensor with Pd electrode on porous ZrO2 thin film has the best sensitivity in term of both adsorption and desorption of gas. This sensor is proved to be operated in both capacitor and diode modes.
The paper demonstrates that room temperature MOS‐based O2 sensor operates in capacitor and diode mode conditions with focus on the effect of ZrO2 surface morphology on the sensing properties.
