A microstructure in an InGaN/GaN layer grown at the semipolar direction was observed in detail by means of transmission electron microscopy (TEM) in order to analyze the behaviour of dislocations. A (112) GaN layer was first deposited on a maskless r (102)-plane patterned-substrate, and then an Inx Ga1-xN (x =0.10, 0.24) was overgrown to be about 1 μm in thickness. Dislocations near the interface of InGaN/GaN are classified into several types: 1 Threading dislocations lying on (0001).
2. Misfit dislocations lying on the interface of InGaN/GaN. 3. Dislocations along  at a certain distance from the interface. 4. Dislocations newly formed at the interface and developing along  on (0001). 5. Partial dislocations accompanied with a stacking fault on (0001).
It was found that the misfit dislocations are arrayed in pairs at the direction along  on the interface of (112). Burgers vector of the misfit dislocations was found to be B = <23>/3. In case of B = /3, they are edge dislocations. The densities of dislocations and stacking faults increase with the In-content in InGaN. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)