Reduced workfunction intermetallic seed layers allow growth of porous n-GaN and low resistivity, ohmic electron transport

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Bilousov, Oleksandr V.
Carvajal, Joan J.
Drouin, Dominique
Mateos, Xavier
Diaz, Francesc
Aguilo, Magdalena
O'Dwyer, Colm
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American Chemical Society (ACS)
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Porous GaN crystals have been successfully grown and electrically contacted simultaneously on Pt- and Au-coated silicon substrates as porous crystals and as porous layers. By the direct reaction of metallic Ga and NH3 gas through chemical vapor deposition, intermetallic metal-Ga alloys form at the GaN–metal interface, allowing vapor–solid–solid seeding and subsequent growth of porous GaN. Current–voltage and capacitance–voltage measurements confirm that the intermetallic seed layers prevent interface oxidation and give a high-quality reduced workfunction contact that allows exceptionally low contact resistivities. Additionally, the simultaneous formation of a lower workfunction intermetallic permits ohmic electron transport to n-type GaN grown using high workfunction metals that best catalyze the formation of porous GaN layers and may be employed to seed and ohmically contact a range of III-N compounds and alloys for broadband absorption and emission.
Ohmic electron transport , Porous GaN , Chemical vapor deposition , Electron transport properties , Gallium alloys , Phase interfaces , Platinum , Vapors , Gallium nitride , Broadband absorption , Capacitance voltage measurements , Contact resistivities , Current voltage , Direct reactions , Electron transport , GaN crystals , GaN layers , High quality , Low resistivity , Porous crystals , Porous GaN , Porous layers , Seed layer , Silicon substrates , Simultaneous formation , Workfunction metals
Bilousov, O. V., Carvajal, J. J., Drouin, D., Mateos, X., Díaz, F., Aguiló, M. and O’Dwyer, C. (2012) 'Reduced Workfunction Intermetallic Seed Layers Allow Growth of Porous n-GaN and Low Resistivity, Ohmic Electron Transport', ACS Applied Materials & Interfaces, 4(12), pp. 6927-6934. doi: 10.1021/am3020668
© 2012 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see