MOCVD法侧向外延生长高质量GaN

利用金属有机物气相外延法(MOCVD)，在GaN/蓝宝石复合衬底上，采用侧向外延生长技术制备出高质量的GaN外延膜，并对其进行扫描电镜、X射线双晶衍射、透射电镜测量和分析. 发现完全合并后的GaN外延层的表面平整，晶体质量较衬底有大幅的提高，透射电镜进行微区位错观察发现窗口区穿透位错大部分发生转向，侧向生长区下方的穿透位错被掩膜阻断.

Epitaxial Lateral Overgrowth of High Quality GaN by MOCVD

High quality of GaN epilayers are obtained by epitaxial lateral overgrowth (ELOG) in a metalorganic chemical vapor deposition on GaN/sapphire composite substrate.The ELOG sample is characterized by scanning electron microscope (SEM),double-crystal X-ray diffraction,and transmission electron microscope (TEM).It is found that the coalescenced GaN layer exhibits smooth surface and the crystalline quality is greatly improved with respect to that of GaN template.TEM results indicate that all the threading dislocations under the mask have been blocked,and most of the threading dislocations within window region have been directed away from along c axis.