AbstractWe report on AlN wafers fabricated by hydride vapor phase epitaxy (HVPE). AlN thick layers were grown on Si substrates by HVPE. Growth rate was up to 60 microns per hour. After the growth of AlN layers, initial substrates were removed resulting in free-standing AlN wafers. The maximum thickness of AlN layer was about 1 mm. AlN free-standing single crystal wafers with a thickness ranging from 0.05 to 0.8 mm were studied by x-ray diffraction, transmission electron microscopy, optical absorption, and cathodoluminescence.
We report on AlN wafers fabricated by hydride vapor phase epitaxy (HVPE). AlN thick layers were grown on Si substrates by HVPE. Growth rate was up to 60 microns per hour. After the growth of AlN layers, initial substrates were removed resulting in free-standing AlN wafers. The maximum thickness of AlN layer was about 1 mm. AlN free-standing single crystal wafers with a thickness ranging from 0.05 to 0.8 mm were studied by x-ray diffraction, transmission electron microscopy, optical absorption, and cathodoluminescence.
AbstractGaN, AIN and AIGaN layers were grown by hydride vapor phase epitaxy. 6H-SiC wafers were used as substrates. Properties of AIN/GaN and AIGaN/GaN structures were investigated. AIGaN growth rate was about 1 μm/min. The thickness of the AIGaN layers ranged from 0.5 to 5 μm. The AIN concentration in AIGaN layers was varied from 9 to 67 mol. %. Samples were characterised by electron beam micro analysis, Auger electron spectroscopy, X-ray diffraction and cathodoluminescence.Electrical measurements performed on AIGaN/GaN/SiC samples indicated that undoped AIGaN layers are conducting at least up to 50 mol. % of AIN.
AbstractYellow luminescence (YL) from GaN was systematically investigated through the intentional introduction of carbon, from propane, and excess H2 during growth by the halide vapor phase epitaxy technique. All GaN films were studied by photoluminescence, X-ray diffraction and Hall measurements. The unintentionally doped GaN showed undetectable or very weak YL signal, while both C-doping and H2 addition resulted in a significant enhancement of YL. The blue- and red-shift of the YL band of the C-doped and ‘H2-grown’ GaN with the increasing temperature indicated that different mechanisms existed in these two cases. The temperature dependence of the integrated intensity of the YL band of both groups implicated that shallow donors, not ‘shallow’ acceptors participated the YL transition and that there were more than one radiative recombination channel within the YL band.
AlN Wafers Fabricated by Hydride Vapor Phase Epitaxy