Low resistance Ti/Al/Mo/Au Ohmic contacts for AlGaN/GaN heterostructure field effect transistors

D. Selvanathan, L. Zhou, V. Kumar, I. Adesida

Research output: Contribution to journalArticlepeer-review

51 Citations (Scopus)

Abstract

A metallization scheme consisting of Ti/Al/Mo/Au was utilized to develop low-resistance ohmic contacts to AlGaN/GaN heterostructure field effect transistors (HFET). A contact resistance as low as 0.20 Ωmm and a specific contact resistivity as low as 4.5 × 10-7 Ωcm2 were obtained using a pre-metallization surface treatment with SiCl4 plasma at a self-bias voltage of -300 V in a reactive ion etching (RIE) system. X-ray photoelectron spectroscopy (XPS) measurements of the SiCl4 plasma-treated surface revealed an increase in the N vacancies thereby increasing the donor concentration at the surface. Also a blue shift of the peak energy of the Ga 3d photoelectrons was observed showing that the Fermi level moved closer to the conduction band at the surface of the AlGaN.

Original languageEnglish
Pages (from-to)583-586
Number of pages4
JournalPhysica Status Solidi (A) Applied Research
Volume194
Issue number2 SPEC.
DOIs
Publication statusPublished - Dec 1 2002

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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