Structural dynamics of GaN microcrystals in Evolutionary Selection Selective Area Growth probed by X-ray microdiffraction.
A method to grow high quality, single crystalline semiconductor material irrespective of the substrate would allow a cost-effective improvement to functionality and performance of optoelectronic devices. Recently, a novel type of substrate-insensitive growth process called Evolutionary Selection Selective Area Growth (ES-SAG) has been proposed. Here we report the use of X-ray microdiffraction to study the structural properties of GaN microcrystals grown by ES-SAG. Utilizing high resolution in both direct and reciprocal spaces, we have unraveled structural dynamics of GaN microcrystals in growth structures of different dimensions. It has been found that the geometric proportions of the growth constrictions play an important role: 2.6 μm and 4.5 μm wide growth tunnels favor the evolutionary selection mechanism, contrary to the case of 8.6 μm growth tunnels. It was also found that GaN microcrystal ensembles are dominated by slight tensile strain irrespective of growth tunnel shape.
Diamond Light Source Ltd, Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE, UK.
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Kachkanov
Department of Electrical Engineering, Yale University, 15 Prospect St, New Haven, CT, 06511, USA.
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Leung
Department of Electrical Engineering, Yale University, 15 Prospect St, New Haven, CT, 06511, USA.
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Song
Department of Electrical Engineering, Yale University, 15 Prospect St, New Haven, CT, 06511, USA.
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Zhang
Department of Electrical Engineering, Yale University, 15 Prospect St, New Haven, CT, 06511, USA.
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Tsai
Department of Electrical Engineering, Yale University, 15 Prospect St, New Haven, CT, 06511, USA.
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Yuan
Department of Electrical Engineering, Yale University, 15 Prospect St, New Haven, CT, 06511, USA.
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J
Han
Department of Physics, SUPA, University of Strathclyde, Glasgow, Scotland, G4 0NG, UK.
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O'Donnell