Films were grown by molecular-beam epitaxy, with intermittent In exposure during film growth, and the microstructures were investigated by atomic-resolution high-voltage electron microscopy. Epitaxial wurtzite GaN (00•1) film grew on a sapphire (00•1) substrate. Although many inversion domains were generated at the film/substrate interface, stacking faults on the basal plane of GaN, which was formed at the position of In exposure, were found to play an important role in terminating the growth of inversion domains. Atomic-resolution high-voltage electron microscopy observations revealed that stacking faults I2 with 2 stacking violations were introduced into the inversion domain while stacking faults I1 with one stacking violation were introduced in the matrix. The difference in the number of stacking violations was related to the change in the inversion domain boundary structure and to the reduction of the inversion domain boundary area. The termination mechanism was considered to be important to the realization of the high-quality GaN film by molecular-beam epitaxy.

Termination Mechanism of Inversion Domains by Stacking Faults in GaN. C.Iwamoto, X.Q.Shen, H.Okumura, H.Matsuhata, Y.Ikuhara: Journal of Applied Physics, 2003, 93[6], 3264-9