A defect selective passivation method to block the propagation of threading dislocations in GaN epitaxial growth was demonstrated. The defect selective passivation was done by using defect selective chemical etching to locate defect sites, followed by silicon oxide passivation of the etched pits, and epitaxial over growth. The threading dislocation density in the re-grown epilayer was significantly improved from 1 x 109 to 4 x 107/cm2. The defect passivated epi-wafer was used to grow light emitting diode and the output power of the fabricated chip was enhanced by 45% at 20mA compared to a reference one without using defect passivation.

Defect Selective Passivation in GaN Epitaxial Growth and its Application to Light Emitting Diodes. M.H.Lo, P.M.Tu, C.H.Wang, Y.J.Cheng, C.W.Hung, S.C.Hsu, H.C.Kuo, H.W.Zan, S.C.Wang, C.Y.Chang, C.M.Liu: Applied Physics Letters, 2009, 95[21], 211103