Ohmic contacts to p-type GaN mediated by polarization fields in thin InxGa1-xN capping layers

T. Gessmann, Y. L. Li, E. L. Waldron, J. W. Graff, E. F. Schubert, J. K. Sheu

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54 Citations (Scopus)


Low-resistance ohmic contacts are demonstrated using thin p-type InGaN layers on p-type GaN. It is shown that the tunneling barrier width is drastically reduced by polarization-induced electric fields in the strained InGaN capping layers resulting in an increase of the hole tunneling probability through the barrier and a significant decrease of the specific contact resistance. The specific contact resistance of Ni (10 nm)/Au (30 nm) contacts deposited on the InGaN capping layers was determined by the transmission line method. Specific contact resistances of 1.2×10-2cm2 and 6×10-3cm2 were obtained for capping layer thicknesses of 20 nm and 2 nm, respectively.

Original languageEnglish
Pages (from-to)986-988
Number of pages3
JournalApplied Physics Letters
Issue number6
Publication statusPublished - 2002 Feb 11

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)


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