It was demonstrated that the density of threading dislocations was sharply reduced by carrying out re-growth on a grooved stripe structure. Threading dislocations in material which was re-grown on grooves tended to propagate off the c-axis, so that an area with a significantly reduced dislocation density was formed above the grooves. As a result, the threading dislocation density was reduced from 5 x 109 to 6.3 x 106/cm2.

Drastic Reduction of Threading Dislocations in GaN Re-Grown on Grooved Stripe Structure. M.Ishida, M.Ogawa, K.Orita, O.Imafuji, M.Yuri, T.Sugino, K.Itoh: Journal of Crystal Growth, 2000, 221, 345-9