Lateral Overgrowth of Thick GaN on Patterned GaN Substrate by Sublimation Technique

Abstract

The lateral overgrowth of thick GaN has been attempted using the sublimation method. The lateral overgrowth of 60 µm on SiO 2 mask, which is about three times larger than the vertical growth, was obtained by one hour of growth at 995°C, with the stripe windows in the <1100> direction of GaN. Transmission electron microscopy (TEM) shows that the extension of threading dislocations is terminated at the SiO 2 /GaN interface. The dislocation density is about 10 9 cm -2 above the window areas, and is reduced to 10 6 cm -2 in the lateral overgrowth region on SiO 2 .