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Title: GaN Schottky diodes with single-crystal aluminum barriers grown by plasma-assisted molecular beam epitaxy

Abstract

GaN-based Schottky barrier diodes (SBDs) with single-crystal Al barriers grown by plasma-assisted molecular beam epitaxy are fabricated. Examined using in-situ reflection high-energy electron diffractions, ex-situ high-resolution x-ray diffractions, and high-resolution transmission electron microscopy, it is determined that epitaxial Al grows with its [111] axis coincident with the [0001] axis of the GaN substrate without rotation. In fabricated SBDs, a 0.2 V barrier height enhancement and 2 orders of magnitude reduction in leakage current are observed in single crystal Al/GaN SBDs compared to conventional thermal deposited Al/GaN SBDs. The strain induced piezoelectric field is determined to be the major source of the observed device performance enhancements.

Authors:
; ; ; ; ; ;  [1];  [2]
  1. Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
  2. Division of Scientific Research, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China)
Publication Date:
OSTI Identifier:
22590521
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM; ELECTRON DIFFRACTION; GALLIUM NITRIDES; MOLECULAR BEAM EPITAXY; MOLECULAR BEAMS; MONOCRYSTALS; PIEZOELECTRICITY; PLASMA; RESOLUTION; SCHOTTKY BARRIER DIODES; STRAINS; SUBSTRATES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION

Citation Formats

Tseng, H. Y., Yang, W. C., Lee, P. Y., Lin, C. W., Cheng, Kai-Yuan, Hsieh, K. C., Cheng, K. Y., E-mail: kycheng@ee.nthu.edu.tw, and Hsu, C.-H. GaN Schottky diodes with single-crystal aluminum barriers grown by plasma-assisted molecular beam epitaxy. United States: N. p., 2016. Web. doi:10.1063/1.4961546.
Tseng, H. Y., Yang, W. C., Lee, P. Y., Lin, C. W., Cheng, Kai-Yuan, Hsieh, K. C., Cheng, K. Y., E-mail: kycheng@ee.nthu.edu.tw, & Hsu, C.-H. GaN Schottky diodes with single-crystal aluminum barriers grown by plasma-assisted molecular beam epitaxy. United States. doi:10.1063/1.4961546.
Tseng, H. Y., Yang, W. C., Lee, P. Y., Lin, C. W., Cheng, Kai-Yuan, Hsieh, K. C., Cheng, K. Y., E-mail: kycheng@ee.nthu.edu.tw, and Hsu, C.-H. 2016. "GaN Schottky diodes with single-crystal aluminum barriers grown by plasma-assisted molecular beam epitaxy". United States. doi:10.1063/1.4961546.
@article{osti_22590521,
title = {GaN Schottky diodes with single-crystal aluminum barriers grown by plasma-assisted molecular beam epitaxy},
author = {Tseng, H. Y. and Yang, W. C. and Lee, P. Y. and Lin, C. W. and Cheng, Kai-Yuan and Hsieh, K. C. and Cheng, K. Y., E-mail: kycheng@ee.nthu.edu.tw and Hsu, C.-H.},
abstractNote = {GaN-based Schottky barrier diodes (SBDs) with single-crystal Al barriers grown by plasma-assisted molecular beam epitaxy are fabricated. Examined using in-situ reflection high-energy electron diffractions, ex-situ high-resolution x-ray diffractions, and high-resolution transmission electron microscopy, it is determined that epitaxial Al grows with its [111] axis coincident with the [0001] axis of the GaN substrate without rotation. In fabricated SBDs, a 0.2 V barrier height enhancement and 2 orders of magnitude reduction in leakage current are observed in single crystal Al/GaN SBDs compared to conventional thermal deposited Al/GaN SBDs. The strain induced piezoelectric field is determined to be the major source of the observed device performance enhancements.},
doi = {10.1063/1.4961546},
journal = {Applied Physics Letters},
number = 8,
volume = 109,
place = {United States},
year = 2016,
month = 8
}
  • The incorporation of deep level defects in n-type GaN grown by plasma assisted molecular beam epitaxy was studied via systematic adjustment of the nitrogen plasma source power from 150 to 400 W while maintaining a constant V/III beam flux ratio. Deep level optical spectroscopy and conventional thermal deep level transient spectroscopy measurements, which together enable deep level detection throughout the GaN band gap, revealed several deep level concentrations that depend strongly on rf-plasma power. The concentrations of the gallium vacancy deep level at E{sub C}-2.60 eV and carbon-related point defects with energy levels at E{sub C}-3.28 and E{sub C}-1.35 eVmore » are found to be very sensitive to the nitrogen source power, increasing by up to 50 times for a corresponding increase in plasma power from 150 to 400 W. The relation between the concentrations of these traps and plasma power follows an Arrhenius-type behavior and is suggestive of plasma damage associated with the energetics of the constituent active nitrogen species. In contrast, two traps at E{sub C}-0.86 and E{sub C}-0.59 eV did not exhibit a systematic dependence on plasma power, with this difference a result of the dislocation-related nature of these defects.« less
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  • No abstract prepared.