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Institute of Korean Electrical and Electronics Engineers (한국전기전자학회)
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Hydrogen Response Characteristics of Tantalum Oxide Layer Formed by Rapid Thermal Oxidation at High Temperatures

고온에서 급속열산화법으로 형성된 탄탈륨산화막의 수소응답특성

  • Seong-Jeen Kim (Dept. of Electronic Engineering, Kyungnam University)
  • Received : 2022.12.20
  • Accepted : 2022.12.26
  • Published : 2023.03.31
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Abstract

Since silicon having a band gap energy of about 1.12 eV are limited to a maximum operating temperature of less than 250 ℃, the sample with MIS structure based on the SiC substrate of wide-band gap energy was manufactured and the hydrogen response characteristics at high temperatures were investigated. The dielectric layer applied here is a tantalum oxide layer that is highly permeable to hydrogen gas and shows stability at high temperatures. It was formed by RTO at a temperature of 900 ℃ with tantalum. The thickness, depth profiles, and leakage current of the tantalum oxide layer were analyzed through TEM, SIMS, and leakage current characteristics. For the hydrogen gas response characteristics, the capacitance change characteristics were investigated in the temperature range from room temperature to 400 ℃ for hydrogen gas concentrations from 0 to 2,000 ppm. As a result, it was confirmed that the sample exhibited excellent sensitivity and a response time of about 60 seconds.

약 1.12 ev의 밴드갭 에너지를 갖는 실리콘은 동작 온도가 250 ℃ 이하로 제한되어, 밴드갭 에너지가 큰 SiC 기판을 이용한 MIS(metal-insulator-semiconductor) 구조의 시료를 제작하여 고온에서 수소 응답 특성을 고찰하였다. 적용된 유전체 박막은 수소가스에 대해 침투성이 강하고 고온에서 안정성을 보이는 탄탈륨 산화막(Ta2O5)으로, 스퍼터링으로 증착된 탄탈륨(Ta)을 900 ℃의 온도에서 급속열산화법(RTO)으로 형성하였다. 이렇게 형성된 탄탈륨 산화막은 TEM, SIMS, 및 누설전류 측정을 통해, 두께, 원소들의 깊이 분포 및 절연특성을 분석하였다. 수소가스 응답특성은 0부터 2,000 ppm의 수소가스 농도에 대해, 상온으로부터 200와 400 ℃의 온도에서 정전용량의 변화로 평가하였다. 그 결과, 시료로부터 감도가 우수하고, 약 60초의 응답 시간을 나타내는 특성을 확인하였다.

Keywords

Acknowledgement

This work was supported by Kyungnam University Foundation Grant, 2022

References

  1. S. Phanichphant, "Semiconductor metal oxides as hydrogen gas sensors," Procedia Engineering, vol.87, pp.795-802, 2014. DOI: 10.1016/j.proeng.2014.11.677 
  2. J. Yu, G. Chen, C. Li, M. Shafiei, J. Ou, J. Plessis, K. Kalantar-zadeh, P. Lai, W. Wlodarski, "Hydrogen gas sensing properties of Pt/Ta2O5 Schottky diodes based on Si and SiC substrates," Sens. Actuator B Chem. vol.172, pp.9-14, 2011. DOI: 10.1016/j.proeng.2010.09.069 
  3. W. M. Tang, C. H. Leung, and P. T. Lai. "Effect of N2-annealing conditions on the sensing properties of Pt/HfO2/SiC Schottky-diode hydrogen sensor," Thin Solid Films, vol.519, pp.505-511, 2010.  https://doi.org/10.1016/j.tsf.2010.08.090
  4. K. Shimizu, I Chinzei, H. Nishiyama, S. Kakimoto, S. Sugaya, H. Yokoi, and A. Satsuma, "Hydrogen sensor based on WO3 subnano-clusters and Pt co-loaded on ZrO2" Sens. Actuators B., vol.134, pp.2618-2624, 2008. DOI: 10.1016/j.snb.2008.06.004 
  5. J. Kanungo, H. Saha, S. Basu, "Effect of porosity on the performance of surface modified porous silicon hydrogen sensors," Sens. Actuator B Chem. vol.147, pp.145-151, 2010. DOI: 10.1016/j.snb.2010.03.001 
  6. C. Lu and Z. Chen, "High-temperature resistive hydrogen sensor based on thin nanoporous rutile TiO2 film on anodic aluminum oxide," Sens. Actuator B., vol.140, pp.109-115, 2009. DOI: 10.1016/j.snb.2009.04.004 
  7. C. Loa, S. W. Tan, C. Y. Wei, J. H. Tsai, and W. S. Lour, "Sensing properties of resistive-type hydrogen sensors with a Pd-SiO2 thin-film mixture," Int. J. Hydrog. Energy, vol.38, pp.313-318, 2013. DOI: 10.1016/j.ijhydene.2012.10.051