Interface state densities near the conduction band edge in N-type 4H- and 6H-SiC

G. Y. Chung, C. C. Tin, J. H. Won, J. R. Williams, K. McDonald, R. A. Weller, S. T. Pantelides, L. C. Feldman

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7 Citations (Scopus)

Abstract

We report the effect on SiO2/SiC interface state density and effective oxide charge of different Si:C ratios (0.12 to 0.55) used during the growth of n-4H and n-6H-SiC epitaxial layers. We also report the effects of post-growth re-oxidation anneals and post-metalization anneals on the interface state density for both n- and p-4H-SiC. The interface trap density near the conduction band and the effective oxide charge increase with increasing Si:C ratio for both polytypes; however, the n-4H polytype is found to have an order of magnitude higher interface trap density near the conduction band compared to n-6H-SiC. The effective oxide charge is also higher for n-4H polytype. The distribution of interface states for 4H-SiC (measured using n- and p-type material) is asymmetric, with a higher trap density near the conduction band. Post-growth re-oxidation in wet O2 at 950°C increases the interface trap density near the conduction for n-4H-SiC. Post-metalization annealing at 450°C in Ar for an Al gate metal results in a reduction of the effective oxide charge from 9.5×1011cm-2 to 3.5×1011cm-2. The effective oxide charge for n-4H samples with Mo gates decreases with increasing post metalization annealing temperature. Interface state densities are not affected by the post-metalization anneals in Ar.

Original languageEnglish
Pages (from-to)409-413
Number of pages5
JournalIEEE Aerospace Conference Proceedings
Volume5
DOIs
Publication statusPublished - Jan 1 2000

ASJC Scopus subject areas

  • Aerospace Engineering
  • Space and Planetary Science

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    Chung, G. Y., Tin, C. C., Won, J. H., Williams, J. R., McDonald, K., Weller, R. A., Pantelides, S. T., & Feldman, L. C. (2000). Interface state densities near the conduction band edge in N-type 4H- and 6H-SiC. IEEE Aerospace Conference Proceedings, 5, 409-413. https://doi.org/10.1109/AERO.2000.878515