Journal of Electronic Materials

, Volume 28, Issue 3, pp 341–346

Effects of annealing in an oxygen ambient on electrical properties of ohmic contacts to p-type GaN

  • Yasuo Koide
  • T. Maeda
  • T. Kawakami
  • S. Fujita
  • T. Uemura
  • N. Shibata
  • Masanori Murakami
Special Issue Paper

Abstract

Effects of annealing ambient of an oxygen and nitrogen mixed gas on the electrical properties were studied for Au-based ohmic contacts (NiAu, CoAu, CuAu, PdAu, and PtAu) to p-type GaN. Addition of oxygen to the nitrogen gas reduced the specific contact resistances (ρc) and resitivities of the p-GaN epilayers (ρs) of the contacts after annealing at temperatures of 500–600°C. The microstructural analysis at the p-GaN/metal interfaces did not detect the heterostructural intermediate semiconductor layer at the GaN/metal interfaces. The reason for reduction of both the ρc and ρs values by the oxygen gas addition was believed to be due to formation of the p-GaN epilayer with high hole concentrations, caused by removal of hydrogen atoms which bonded with Mg atoms.

Key words

Annealing contact resistance contact ohmic p-GaN 

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Copyright information

© TMS-The Minerals, Metals and Materials Society 1999

Authors and Affiliations

  • Yasuo Koide
    • 1
  • T. Maeda
    • 1
  • T. Kawakami
    • 1
  • S. Fujita
    • 1
  • T. Uemura
    • 2
  • N. Shibata
    • 2
  • Masanori Murakami
    • 3
  1. 1.Department of Materials Science and EngineeringKyoto UniversitySakyo-ku, KyotoJapan
  2. 2.Technical Department of OptelectronicsToyoda Gosei Co., Ltd.AichiJapan
  3. 3.Department of Materials Science and EngineeringKyoto UniversitySakyo-ku, KyotoJapan

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