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Title: Step edge influence on barrier height and contact area in vertical heterojunctions between epitaxial graphene and n-type 4H-SiC

Vertical rectifying contacts of epitaxial graphene grown by Si sublimation on the Si-face of 4H-SiC epilayers were investigated. Forward bias preferential conduction through the step edges was correlated by linear current density normalization. This phenomenon was observed on samples with 2.7–5.8 monolayers of epitaxial graphene as determined by X-ray photoelectron spectroscopy. A modified Richardson plot was implemented to extract the barrier height (0.81 eV at 290 K, 0.99 eV at 30 K) and the electrically dominant SiC step length of a Ti/Al contact overlapping a known region of approximately 0.52 μm wide SiC terraces.
Authors:
; ;  [1] ; ; ; ; ; ; ; ;  [2]
  1. American Society for Engineering Education, Washington, DC 20036 (United States)
  2. U.S. Naval Research Laboratory, 4555 Overlook Ave, SW, Washington, DC 20375 (United States)
Publication Date:
OSTI Identifier:
22283294
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 7; 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; APPROXIMATIONS; CURRENT DENSITY; EPITAXY; GRAPHENE; HETEROJUNCTIONS; N-TYPE CONDUCTORS; SILICON; SILICON CARBIDES; SUBLIMATION; TEMPERATURE DEPENDENCE; X-RAY PHOTOELECTRON SPECTROSCOPY