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Title: The significant effect of the thickness of Ni film on the performance of the Ni/Au Ohmic contact to p-GaN

The significant effect of the thickness of Ni film on the performance of the Ohmic contact of Ni/Au to p-GaN is studied. The Ni/Au metal films with thickness of 15/50 nm on p-GaN led to better electrical characteristics, showing a lower specific contact resistivity after annealing in the presence of oxygen. Both the formation of a NiO layer and the evolution of metal structure on the sample surface and at the interface with p-GaN were checked by transmission electron microscopy and energy-dispersive x-ray spectroscopy. The experimental results indicate that a too thin Ni film cannot form enough NiO to decrease the barrier height and get Ohmic contact to p-GaN, while a too thick Ni film will transform into too thick NiO cover on the sample surface and thus will also deteriorate the electrical conductivity of sample.
Authors:
; ; ; ; ; ; ; ;  [1] ; ; ;  [2] ;  [1] ;  [3]
  1. State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Science, P.O. Box 912, Beijing 100083 (China)
  2. Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China)
  3. (China)
Publication Date:
OSTI Identifier:
22308158
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; ELECTRIC CONDUCTIVITY; ELECTRIC POTENTIAL; EVOLUTION; FILMS; GALLIUM NITRIDES; GOLD; INTERFACES; LAYERS; NICKEL; NICKEL OXIDES; OXYGEN; P-TYPE CONDUCTORS; SURFACES; THICKNESS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY SPECTROSCOPY