Nanoscale conductive pattern of the homoepitaxial AlGaN/GaN transistor
Perez-Tomas, Amador (Institut Català de Nanociència i Nanotecnologia)
Catalan, Gustau (Institut Català de Nanociència i Nanotecnologia)
Fontserè Recuenco, Abel (ALBA Laboratori de Llum de Sincrotró)
Iglesias Santiso, Vanessa (Universitat Autònoma de Barcelona. Escola d'Enginyeria)
Chen, H. (University of Warwick. School of Engineering)
Gammon, Peter (University of Warwick. School of Engineering)
Jennings, M. R. (University of Warwick. School of Engineering)
Thomas, M. (University of Warwick. School of Engineering)
Fisher, C. A. (University of Warwick. School of Engineering)
Sharma, Y. K. (University of Warwick. School of Engineering)
Placidi, Marcel (Institut de Recerca en Energia de Catalunya)
Chmielowska, M. (Centre National de la Recherche Scientifique (França). Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications)
Chenot, S. (Centre National de la Recherche Scientifique (França). Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications)
Porti i Pujal, Marc (Universitat Autònoma de Barcelona. Escola d'Enginyeria)
Nafría i Maqueda, Montserrat (Universitat Autònoma de Barcelona. Escola d'Enginyeria)
Cordier, Y. (Centre National de la Recherche Scientifique (França). Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications)

Date:	2015
Abstract:	The gallium nitride (GaN)-based buffer/barrier mode of growth and morphology, the transistor electrical response (25-310°C) and the nanoscale pattern of a homoepitaxial AlGaN/GaN high electron mobility transistor (HEMT) have been investigated at the micro and nanoscale. The low channel sheet resistance and the enhanced heat dissipation allow a highly conductive HEMT transistor (Ids > 1 A mmˉ¹) to be defined (0. 5 A mm¯¹ at 300 °C). The vertical breakdown voltage has been determined to be ~850 V with the vertical drain-bulk (or gate-bulk) current following the hopping mechanism, with an activation energy of 350 meV. The conductive atomic force microscopy nanoscale current pattern does not unequivocally follow the molecular beam epitaxy AlGaN/GaN morphology but it suggests that the FS-GaN substrate presents a series of preferential conductive spots (conductive patches). Both the estimated patches density and the apparent random distribution appear to correlate with the edge-pit dislocations observed via cathodoluminescence. The sub-surface edge-pit dislocations originating in the FS-GaN substrate result in barrier height inhomogeneity within the HEMT Schottky gate producing a subthreshold current.
Grants:	Ministerio de Economía y Competitividad SEV-2013-0295
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Published in:	Nanotechnology, Vol. 26, Issue 11 (March 2015) , art. 115203, ISSN 1361-6528

DOI: 10.1088/0957-4484/26/11/115203

Postprint 21 p, 746.1 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > The ALBA Synchrotron
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