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研究了在刻有图形的GaN“衬底”上用HVPE方法侧向外延生长 (ELO)GaN的结构特性。在SiO2 衬底上侧向外延生长GaN已经实现 ,并得到了平面的ELOGaN薄膜。采用扫描电子显微镜、透射电微镜和原子力显微镜技术研究了这种ELOGaN材料的结构和表面形貌。原子力显微镜图像表明 :在ELO范围中的4 μm2 面积上不存在明显的阶状形貌。透射电子显微镜的观测表明在ELO范围内位错密度很低。在接合的界面上没观察到有空隙存在。但观测到晶格的弯曲高达 3 3°,这被归因为由GaN层下的“籽层”和接合界面处的水平倾料和猝灭所产生的螺旋位错的积聚。
The structural properties of laterally epitaxially grown (ELO) GaN by the HVPE method on a patterned GaN “substrate” were investigated. Lateral epitaxial growth of GaN on a SiO2 substrate has been achieved and a planar ELOGaN film has been obtained. The structure and surface morphology of ELOGaN materials were investigated by scanning electron microscopy, transmission electron microscopy and atomic force microscopy. Atomic force microscopy images showed that there was no obvious step-like morphology on the 4 μm2 area in the ELO range. Transmission electron microscopy observations indicate that the dislocation density is low in the ELO range. No voids were observed on the bonded interface. However, bending of the lattice was observed up to 33 ° due to the accumulation of helical dislocations resulting from the “seed layer” beneath the GaN layer and the horizontal dumping and quenching at the bonding interface.