【摘要】 采用侧向外延(ELOG)方法,在制作了条形掩膜图形的GaN衬底上用MOCVD生长高质量GaN.AFM,化学湿法腐蚀及TEM分析表明:采用两步法ELOG生长的GaN中,掩膜下方的缺陷被掩膜所阻挡,窗口区内二次生长的GaN的位错也大幅降低;在相邻生长前沿所形成的合并界面处形成晶界;化学湿法腐蚀无法得到关于合并界面处缺陷的信息.侧翼区域中极低的穿透位错使得ELOG GaN适用于在其上制作高性能的氮化物基激光器.更多还原

【Abstract】 High quality GaN is grown on GaN substrate with stripe pattern by metalorganic chemical vapor deposition by means of epitaxial lateral overgrowth.AFM,wet chemical etching,and TEM experiments show that with a two-step ELOG procedure,the propagation of defects under the mask is blocked,and the coherently grown GaN above the window also experiences a drastic reduction in defect density.In addition,a grain boundary is formed at the coalescence boundary of neighboring growth fronts.The extremely low density of threading dislocations within wing regions makes ELOG GaN a potential template for the fabrication of nitride-based lasers with improved performance.更多还原