材料期刊网

A novel structure defect in epitaxial wurtzite GaN film is reported in this paper. It is: observed as an isolated (11 (2) over bar 0) planar defect within one large perfect crystal area by high-resolution electron microscopy. By careful analysis of the experimental atomic image it is found that the atomic structure is composed of Ga-Ga and N-N like-atom bonds. It forms a segment of a high-energy boundary by theoretical considerations. The reason for the defect formation is explained from the mechanism of epitaxial film growth. The defect is considered an incipient (11 (2) over bar 0) edge dislocation. (C) 1999 Elsevier Science B.V. All rights reserved.