Concentration, chemical bonding, and etching behavior of P and N at the SiO2/SiC(0001) interface

Y. Xu, C. Xu, G. Liu, H. D. Lee, S. M. Shubeita, C. Jiao, A. Modic, A. C. Ahyi, Y. Sharma, A. Wan, J. R. Williams, T. Gustafsson, S. Dhar, Eric Garfunkel, Leonard C Feldman

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Abstract

Phosphorous and nitrogen are electrically active species at the SiO2/SiC interface in SiC MOSFETs. We compare the concentration, chemical bonding, and etching behavior of P and N at the SiO2/SiC(0001) interface using photoemission, ion scattering, and secondary ion mass spectrometry. Both interfacial P and N are found to be resistant to buffered HF solution etching at the SiO2/SiC(0001) interface while both are completely removed from the SiO2/Si interface. The medium energy ion scattering results of etched phosphosilicate glass/SiC not only provide an accurate coverage but also indicate that both the passivating nitrogen and phosphorus are confined to within 0.5 nm of the interface. Angle resolved photoemission shows that P and N are likely situated in different chemical environments at the interface. We conclude that N is primarily bound to Si atoms at the interface while P is primarily bound to O and possibly to Si or C. Different interface passivating element coverages and bonding configurations on different SiC crystal faces are also discussed. The study provides insights into the mechanisms by which P and N passivate the SiO2/SiC(0001) interface and hence improve the performance of SiC MOSFETs.

Original languageEnglish
Article number235303
JournalJournal of Applied Physics
Volume118
Issue number23
DOIs
Publication statusPublished - Dec 21 2015

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Xu, Y., Xu, C., Liu, G., Lee, H. D., Shubeita, S. M., Jiao, C., Modic, A., Ahyi, A. C., Sharma, Y., Wan, A., Williams, J. R., Gustafsson, T., Dhar, S., Garfunkel, E., & Feldman, L. C. (2015). Concentration, chemical bonding, and etching behavior of P and N at the SiO2/SiC(0001) interface. Journal of Applied Physics, 118(23), [235303]. https://doi.org/10.1063/1.4937400