Microstructure of non-polar GaN on LiGaO 2 grown by plasma-assisted MBE

Abstract

We have investigated the structure of non-polar GaN, both on the M - and A-plane, grown on LiGaO 2 by plasmaassisted molecular beam epitaxy. The epitaxial relationship and the microstructure of the GaN films are investigated by transmission electron microscopy (TEM). The already reported epi-taxial relationship [1120] GaN{double pipe}[010] LGO and (1100) GaN{double pipe}(100) LGO for M -plane GaN is confirmed. The main defects are threading dislocations and stacking faults in both samples. For the M -plane sample, the density of threading dislocations is around 1 × 10 11 cm -2 and the stacking fault density amounts to approximately 2 × 10 5 cm -1. In the A-plane sample, a threading dislocation density in the same order was found, while the stacking fault density is much lower than in the M -plane sample. © 2011 Shih et al.