Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot Formation

We investigate the electrical characteristics of Schottky contacts for an Au/hydride vapor phase epitaxy (HVPE) a-plane GaN template grown via in situ GaN nanodot formation. Although the Schottky diodes present excellent rectifying characteristics, their Schottky barrier height and ideality factor a...

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Main Authors: Moonsang Lee, Thi Kim Oanh Vu, Kyoung Su Lee, Eun Kyu Kim, Sungsoo Park
Format: Article
Language:English
Published: MDPI AG 2018-06-01
Series:Nanomaterials
Subjects:
Online Access:http://www.mdpi.com/2079-4991/8/6/397
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author Moonsang Lee
Thi Kim Oanh Vu
Kyoung Su Lee
Eun Kyu Kim
Sungsoo Park
author_facet Moonsang Lee
Thi Kim Oanh Vu
Kyoung Su Lee
Eun Kyu Kim
Sungsoo Park
author_sort Moonsang Lee
collection DOAJ
description We investigate the electrical characteristics of Schottky contacts for an Au/hydride vapor phase epitaxy (HVPE) a-plane GaN template grown via in situ GaN nanodot formation. Although the Schottky diodes present excellent rectifying characteristics, their Schottky barrier height and ideality factor are highly dependent upon temperature variation. The relationship between the barrier height, ideality factor, and conventional Richardson plot reveals that the Schottky diodes exhibit an inhomogeneous barrier height, attributed to the interface states between the metal and a-plane GaN film and to point defects within the a-plane GaN layers grown via in situ nanodot formation. Also, we confirm that the current transport mechanism of HVPE a-plane GaN Schottky diodes grown via in situ nanodot formation prefers a thermionic field emission model rather than a thermionic emission (TE) one, implying that Poole–Frenkel emission dominates the conduction mechanism over the entire range of measured temperatures. The deep-level transient spectroscopy (DLTS) results prove the presence of noninteracting point-defect-assisted tunneling, which plays an important role in the transport mechanism. These electrical characteristics indicate that this method possesses a great throughput advantage for various applications, compared with Schottky contact to a-plane GaN grown using other methods. We expect that HVPE a-plane GaN Schottky diodes supported by in situ nanodot formation will open further opportunities for the development of nonpolar GaN-based high-performance devices.
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spelling doaj.art-60ea1c67ab92475586d772cd084427b62022-12-22T00:46:11ZengMDPI AGNanomaterials2079-49912018-06-018639710.3390/nano8060397nano8060397Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot FormationMoonsang Lee0Thi Kim Oanh Vu1Kyoung Su Lee2Eun Kyu Kim3Sungsoo Park4Korea Basic Science Institute, 169-148, Gwahak-ro, Yuseong-gu, 34133 Daejeon, KoreaQuantum-Function Research Laboratory and Department of Physics, Hanyang University, 04763 Seoul, KoreaQuantum-Function Research Laboratory and Department of Physics, Hanyang University, 04763 Seoul, KoreaQuantum-Function Research Laboratory and Department of Physics, Hanyang University, 04763 Seoul, KoreaDepartment of Science Education, Jeonju University, 303 Cheonjam-ro, Wansan-gu, 55069 Jeollabuk-do, KoreaWe investigate the electrical characteristics of Schottky contacts for an Au/hydride vapor phase epitaxy (HVPE) a-plane GaN template grown via in situ GaN nanodot formation. Although the Schottky diodes present excellent rectifying characteristics, their Schottky barrier height and ideality factor are highly dependent upon temperature variation. The relationship between the barrier height, ideality factor, and conventional Richardson plot reveals that the Schottky diodes exhibit an inhomogeneous barrier height, attributed to the interface states between the metal and a-plane GaN film and to point defects within the a-plane GaN layers grown via in situ nanodot formation. Also, we confirm that the current transport mechanism of HVPE a-plane GaN Schottky diodes grown via in situ nanodot formation prefers a thermionic field emission model rather than a thermionic emission (TE) one, implying that Poole–Frenkel emission dominates the conduction mechanism over the entire range of measured temperatures. The deep-level transient spectroscopy (DLTS) results prove the presence of noninteracting point-defect-assisted tunneling, which plays an important role in the transport mechanism. These electrical characteristics indicate that this method possesses a great throughput advantage for various applications, compared with Schottky contact to a-plane GaN grown using other methods. We expect that HVPE a-plane GaN Schottky diodes supported by in situ nanodot formation will open further opportunities for the development of nonpolar GaN-based high-performance devices.http://www.mdpi.com/2079-4991/8/6/397nanodota-plane GaNHVPESchottky diodes
spellingShingle Moonsang Lee
Thi Kim Oanh Vu
Kyoung Su Lee
Eun Kyu Kim
Sungsoo Park
Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot Formation
Nanomaterials
nanodot
a-plane GaN
HVPE
Schottky diodes
title Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot Formation
title_full Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot Formation
title_fullStr Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot Formation
title_full_unstemmed Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot Formation
title_short Electronic Transport Mechanism for Schottky Diodes Formed by Au/HVPE a-Plane GaN Templates Grown via In Situ GaN Nanodot Formation
title_sort electronic transport mechanism for schottky diodes formed by au hvpe a plane gan templates grown via in situ gan nanodot formation
topic nanodot
a-plane GaN
HVPE
Schottky diodes
url http://www.mdpi.com/2079-4991/8/6/397
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