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Title: Ohmic contacts to Al-rich AlGaN heterostructures

Abstract

Due to the ultra-wide bandgap of Al-rich AlGaN, up to 5.8 eV for the structures in this study, obtaining low resistance ohmic contacts is inherently difficult to achieve. A comparative study of three different fabrication schemes is presented for obtaining ohmic contacts to an Al-rich AlGaN channel. Schottky-like behavior was observed for several different planar metallization stacks (and anneal temperatures), in addition to a dry-etch recess metallization contact scheme on Al0.85Ga0.15N/Al0.66Ga0.34N. However, a dry etch recess followed by n+-GaN regrowth fabrication process is reported as a means to obtain lower contact resistivity ohmic contacts on a Al0.85Ga0.15N/Al0.66Ga0.34N heterostructure. In conclusion, specific contact resistivity of 5×10-3 Ω cm2 was achieved after annealing Ti/Al/Ni/Au metallization.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
1398780
Alternate Identifier(s):
OSTI ID: 1374948
Report Number(s):
SAND-2017-9872J
Journal ID: ISSN 1862-6300; 656978
Grant/Contract Number:  
AC04-94AL85000
Resource Type:
Accepted Manuscript
Journal Name:
Physica Status Solidi. A, Applications and Materials Science
Additional Journal Information:
Journal Volume: 214; Journal Issue: 8; Journal ID: ISSN 1862-6300
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AlGaN; AlN; band gap; heterostructures; ohmic contacts

Citation Formats

Douglas, E. A., Reza, S., Sanchez, C., Koleske, D., Allerman, A., Klein, B., Armstrong, A. M., Kaplar, R. J., and Baca, A. G. Ohmic contacts to Al-rich AlGaN heterostructures. United States: N. p., 2017. Web. doi:10.1002/pssa.201600842.
Douglas, E. A., Reza, S., Sanchez, C., Koleske, D., Allerman, A., Klein, B., Armstrong, A. M., Kaplar, R. J., & Baca, A. G. Ohmic contacts to Al-rich AlGaN heterostructures. United States. doi:10.1002/pssa.201600842.
Douglas, E. A., Reza, S., Sanchez, C., Koleske, D., Allerman, A., Klein, B., Armstrong, A. M., Kaplar, R. J., and Baca, A. G. Tue . "Ohmic contacts to Al-rich AlGaN heterostructures". United States. doi:10.1002/pssa.201600842. https://www.osti.gov/servlets/purl/1398780.
@article{osti_1398780,
title = {Ohmic contacts to Al-rich AlGaN heterostructures},
author = {Douglas, E. A. and Reza, S. and Sanchez, C. and Koleske, D. and Allerman, A. and Klein, B. and Armstrong, A. M. and Kaplar, R. J. and Baca, A. G.},
abstractNote = {Due to the ultra-wide bandgap of Al-rich AlGaN, up to 5.8 eV for the structures in this study, obtaining low resistance ohmic contacts is inherently difficult to achieve. A comparative study of three different fabrication schemes is presented for obtaining ohmic contacts to an Al-rich AlGaN channel. Schottky-like behavior was observed for several different planar metallization stacks (and anneal temperatures), in addition to a dry-etch recess metallization contact scheme on Al0.85Ga0.15N/Al0.66Ga0.34N. However, a dry etch recess followed by n+-GaN regrowth fabrication process is reported as a means to obtain lower contact resistivity ohmic contacts on a Al0.85Ga0.15N/Al0.66Ga0.34N heterostructure. In conclusion, specific contact resistivity of 5×10-3 Ω cm2 was achieved after annealing Ti/Al/Ni/Au metallization.},
doi = {10.1002/pssa.201600842},
journal = {Physica Status Solidi. A, Applications and Materials Science},
number = 8,
volume = 214,
place = {United States},
year = {2017},
month = {6}
}

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