Epitaxial lateral overgrowth of GaN over AlOx surface formed on Si substrate

An approach by which single crystal alpha-GaN can be grown laterally over oxidized AlAs (AlOx) formed on Si substrates is demonstrated. Regular alpha-Ga-2-O-3 stripe templates, spatially separated by AlOx, on which subsequent GaN growth is selectively seeded are formed. Since the boundary between the stripe template and AlOx is nominally planar, two pyramidal planes on separated GaN can merge by growing laterally over the AlOx (referred to as planar epitaxial lateral overgrowth). Transmission electron microscopy reveals that the number of structural defects in GaN laterally grown over the AlOx is remarkably reduced compared to that in GaN grown on the stripe templates, and accordingly cathodoluminescence reveals a strong band edge emission from GaN laterally grown over the AlOx, suggesting that this approach allows us to grow GaN on Si substrates with fewer defects. (C) 1999 American Institute of Physics. [S0003-6951(99)03019-3].