Functional room temperature metal (Al or Pd)‐ZrO₂ (smooth or porous surface)‐Si MOS capacitor O₂ sensor

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Citation

Teng Soo, M., Yew Cheon, K. and Fauzi Mohd Noor, A. (2011), "Functional room temperature metal (Al or Pd)‐ZrO₂ (smooth or porous surface)‐Si MOS capacitor O₂ sensor", Microelectronics International, Vol. 28 No. 1, pp. 50-57. https://doi.org/10.1108/13565361111097119