MOS hydrogen sensor with very fast response based on ultra-thin thermal SiO2 film

Chi Lu, Zhi Chen

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


An MOS capacitor-type hydrogen gas sensor was fabricated with the structure of Ni/SiO2/Si by using conventional silicon wafer technologies. Grown by dry oxidation at 900°C, the thickness of the SiO2 film was only 24 . At 150°C, comparing to another MOS capacitor with 148 -thick oxide and otherwise identical configurations, this sensor showed much faster response speed (the time interval to reach half of the magnitude of the steady-state signal, or t50%, was only 4 s in response to 1% H 2 without deduction of the delay from the gas delivery system), as well as enhanced signal magnitude (about two times of the former for 1% H 2). Based on the hydrogen-binding to the traps in the bulk SiO 2, a mechanism was proposed to explain the very short response time on the device with the ultra-thin SiO2. The gate leakage in the device is also discussed. The presented sensor demonstrates a promising step in designing low-cost H2 detectors with very fast responses.

Original languageEnglish
Pages (from-to)12561-12567
Number of pages7
JournalInternational Journal of Hydrogen Energy
Issue number22
StatePublished - Nov 2010

Bibliographical note

Funding Information:
This research work was supported by the Department of Energy (DE-FG26-04NT42171) and National Science Foundation (ECS-0609064). We thank Dr. Shibin Li and Ms. Jing Guo for technical assistance.


  • H sensor
  • MOS capacitor
  • Response time
  • SiO bulk trap
  • Ultra-thin thermal SiO film

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology


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