Extended defect reduction in GaN could be achieved via direct growth on stripe patterned (11¯•2) r-plane sapphire substrates by metal organic chemical vapour deposition. The striped mesa was along [11•0] with two etched sides in {00•1} and {11¯•1} faces. GaN grown on both etched facets in epitaxy exhibited different crystallographic relationships with sapphire substrate which were (11¯•2)sapphire||(11•0)GaN and [11•0]sapphire||[1¯1•0]GaN, and (00•1)sapphire||(00•1)GaN and [11•0]sapphire||[1¯1•0]GaN, respectively. The dislocation densities could be significantly reduced through epitaxial growth on the inclined lateral faces of mesas. Dislocation density in the order of ~107/cm2 could be achieved in the tilted GaN.

Dislocation Reduction in GaN Grown on Stripe Patterned r-Plane Sapphire Substrates. H.G.Chen, T.S.Ko, S.C.Ling, T.C.Lu, H.C.Kuo, S.C.Wang, Y.H.Wu, L.Chang: Applied Physics Letters, 2007, 91[2], 021914