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Title: An AlN/Al0.85Ga0.15N High Electron Mobility Transistor with A Regrown Ohmic Contact.

Abstract

Abstract not provided.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1366827
Report Number(s):
SAND2016-5836C
642225
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: Proposed for presentation at the 74th Device Research Conference held June 19-22, 2016 in Newark, DE.
Country of Publication:
United States
Language:
English

Citation Formats

Baca, Albert G., Armstrong, Andrew, Allerman, Andrew A., Douglas, Erica Ann, Sanchez, Carlos Anthony, King, Michael Patrick, Coltrin, Michael E., Nordquist, Christopher, Fortune, Torben Ray, and Kaplar, Robert. An AlN/Al0.85Ga0.15N High Electron Mobility Transistor with A Regrown Ohmic Contact.. United States: N. p., 2016. Web.
Baca, Albert G., Armstrong, Andrew, Allerman, Andrew A., Douglas, Erica Ann, Sanchez, Carlos Anthony, King, Michael Patrick, Coltrin, Michael E., Nordquist, Christopher, Fortune, Torben Ray, & Kaplar, Robert. An AlN/Al0.85Ga0.15N High Electron Mobility Transistor with A Regrown Ohmic Contact.. United States.
Baca, Albert G., Armstrong, Andrew, Allerman, Andrew A., Douglas, Erica Ann, Sanchez, Carlos Anthony, King, Michael Patrick, Coltrin, Michael E., Nordquist, Christopher, Fortune, Torben Ray, and Kaplar, Robert. Wed . "An AlN/Al0.85Ga0.15N High Electron Mobility Transistor with A Regrown Ohmic Contact.". United States. doi:. https://www.osti.gov/servlets/purl/1366827.
@article{osti_1366827,
title = {An AlN/Al0.85Ga0.15N High Electron Mobility Transistor with A Regrown Ohmic Contact.},
author = {Baca, Albert G. and Armstrong, Andrew and Allerman, Andrew A. and Douglas, Erica Ann and Sanchez, Carlos Anthony and King, Michael Patrick and Coltrin, Michael E. and Nordquist, Christopher and Fortune, Torben Ray and Kaplar, Robert},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jun 01 00:00:00 EDT 2016},
month = {Wed Jun 01 00:00:00 EDT 2016}
}

Conference:
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  • Abstract not provided.
  • This paper correlates the micro-structural and electrical characteristics associated with annealing of metallic multi-layers typically used in the formation of Ohmic contacts to InAlN high electron mobility transistors. The multi-layers comprised Ti/Al/Ni/Au and were annealed via rapid thermal processing at temperatures up to 925 °C with electrical current-voltage analysis establishing the onset of Ohmic (linear IV) behaviour at 750–800 °C. In-situ temperature dependent transmission electron microscopy established that metallic diffusion and inter-mixing were initiated near a temperature of 500 °C. Around 800 °C, inter-diffusion of the metal and semiconductor (nitride) was observed, correlating with the onset of Ohmic electrical behaviour. The sheet resistance associatedmore » with the InAlN/AlN/GaN interface is highly sensitive to the anneal temperature, with the range depending on the Ti layer thickness. The relationship between contact resistivity and measurement temperature follow that predicted by thermionic field emission for contacts annealed below 850 °C, but deviated above this due to excessive metal-semiconductor inter-diffusion.« less
  • Ohmic contacts fabricated by regrowth of n{sup +} GaN are favorable alternatives to metal-stack-based alloyed contacts in GaN-based high electron mobility transistors. In this paper, the influence of reactive ion dry etching prior to regrowth on the contact resistance in AlGaN/GaN devices is discussed. We demonstrate that the dry etch conditions modify the surface band bending, dangling bond density, and the sidewall depletion width, which influences the contact resistance of regrown contacts. The impact of chemical surface treatments performed prior to regrowth is also investigated. The sensitivity of the contact resistance to the surface treatments is found to depend uponmore » the dangling bond density of the sidewall facets exposed after dry etching. A theoretical model has been developed in order to explain the observed trends.« less
  • Investigations of Ti/Al/Mo/Au Ohmic contact formation, premetallization plasma treatment effects, and interfacial reactions for n{sup +}-GaN capped AlGaN/AlN/GaN heterostructures are presented. Ti thickness played an important role in determining contact performance. Transmission electron microscopy studies confirmed that thick Ti layer was necessary to fully consume the GaN cap and the top of AlGaN to enable a higher tunneling current flow. A direct correlation of plasma treatment conditions with I-V linearity, current level, and contact performance was established. The plasma-affected region is believed to extend over 20 nm into the AlGaN and GaN.
  • Low defect AlN/GaN high electron mobility transistor (HEMT) structures, with very high values of electron mobility (>1800 cm{sup 2}/V s) and sheet charge density (>3x10{sup 13} cm{sup -2}), were grown by rf plasma-assisted molecular beam epitaxy (MBE) on sapphire and SiC, resulting in sheet resistivity values down to {approx}100 {omega}/{open_square} at room temperature. Fabricated 1.2 {mu}m gate devices showed excellent current-voltage characteristics, including a zero gate saturation current density of {approx}1.3 A/mm and a peak transconductance of {approx}260 mS/mm. Here, an all MBE growth of optimized AlN/GaN HEMT structures plus the results of thin-film characterizations and device measurements are presented.