Interface state density and channel mobility for 4H-SiC MOSFETs with nitrogen passivation

G. Y. Chung, J. R. Williams, C. C. Tin, K. McDonald, D. Farmer, R. K. Chanana, S. T. Pantelides, O. W. Holland, L. C. Feldman

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Abstract

Interface state density and channel mobility have been characterized for 4H-SiC MOSFETs fabricated with dry thermal oxides and subsequently passivated with nitric oxide. The interface trap density at 0.1eV below the conduction band edge decreases from approximately 8 × 10 12 to 1 × 10 12 eV -1 cm -2 following anneals in nitric oxide (NO) at 1175°C for 2h. The room temperature field effect channel mobility increases by an order of magnitude to approximately 35 cm 2 /Vs following the passivation anneal. The field effect channel mobility of passivated MOSFETs shows almost no change with increasing temperature, while the mobility for unpassivated devices increases with increasing temperature and is thermally activated (∼T 1.9 ) due to decreased Coulomb scattering by electrons trapped at the acceptor-like interface states near the conduction band. Over the temperature range 300-473K, threshold voltage changes of about -0.8 and -3.7V, respectively, are observed for devices processed with and without NO passivation.

Original languageEnglish
Pages (from-to)399-403
Number of pages5
JournalApplied Surface Science
Volume184
Issue number1-4
DOIs
Publication statusPublished - Dec 12 2001

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Keywords

  • Interface states
  • MOSFETs
  • Mobility
  • Nitration
  • Silicon carbide
  • Threshold voltage

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

Cite this

Chung, G. Y., Williams, J. R., Tin, C. C., McDonald, K., Farmer, D., Chanana, R. K., Pantelides, S. T., Holland, O. W., & Feldman, L. C. (2001). Interface state density and channel mobility for 4H-SiC MOSFETs with nitrogen passivation. Applied Surface Science, 184(1-4), 399-403. https://doi.org/10.1016/S0169-4332(01)00684-5