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Title of article :
Buffer design for nitrogen polarity GaN on sapphire image by RF-MBE and application to the nanostructure formation using KOH etching
Author/Authors :
Ryuji Katayama، نويسنده , , Kentaro Onabe، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2006
Pages :
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Abstract :
GaN films were grown by radiofrequency plasma-assisted molecular beam epitaxy on a variety of sapphire View the MathML source substrates with different buffer layer and/or preparation processes, to show the controllability of lattice-polarity selection as well as their applicability to the nanostructure fabrication. Film polarities, which have been checked by reflection high-energy electron diffraction reconstructions and etched morphologies in KOH aqueous solution, were very sensitive to these preparation processes. Ga-polarity GaN could be obtained by an introduction of a high-temperature nitridation and an AlN interlayer deposition, and the N-polarity film with a flat surface and large grains could be grown on a low-temperature-nitrided sapphire in combination with a use of nitrogen-flux modulation sequence, while other pretreatment resulted in the mixed polarities. The resultant morphology of N-polarity GaN after KOH etching clearly reflects crystallographic orientation and the highly anisotropic-etching behavior show the usefulness of the low-temperature-nitrided sapphire for obtaining large-domain N-polarity GaN and the feasibility of nanostructure fabrication without the use of an expensive dry-etching process.
Keywords :
GaN , RF-MBE , Polarity , KOH etching
Journal title :
Physica E Low-dimensional Systems and Nanostructures
Link To Document :