利用高性能阴极荧光(CL)联合分析系统结合场发射扫描电镜对使用MOCVD方法在蓝宝石衬底上实现的不同生长温度条件下InGaN/GaN薄膜材料进行测试分析。利用CL紫外可见光谱系统,对(0001)面蓝宝石衬底上生长的InGaN/GaN薄膜进行阴极荧光单色谱测试分析,揭示了CL的发光波长与In成分变化之间的关系,即随着薄膜中In含量的降低CL谱峰值波长随之产生蓝移。为了进一步研究InGaN薄膜材料的发光机制及薄膜中出现的V坑,对InGaN/GaN薄膜材料进行了同一位置的SEM图像和CLMapping的对比分析,探讨了缺陷与发光的关系。认定了薄膜中出现的大尺寸V坑对InGaN薄膜材料的发光没有帮助;小尺寸V坑被认定为热腐蚀坑,也对薄膜发光没有贡献。结合sEM图像和CLMapping初步确认了部分In富集区域。同时研究了InGaN/GaN薄膜表面形貌的平坦区域与沟壑区域造成的发光波动。
By using high-performance cathodoluminescence unitized systems and SEM tested the InGaN/GaN film which was grown on the sapphire substrates with MOCVD in different growth temperature conditions. With the CL UV, the InGaN/GaN film that grew on the (0001) surface of sapphire substrates was tested and analyzed. It was proclaimed the relationship between the CL fluorescent light wavelengths and the composition change of In, the result showed that in the film with the decreasing of In the CL spectrum peak wave- length generated a blue shift. In order to further research the emitting mechanism of InGaN film material and V-defect that appeared in the film, the SEM image and CL mapping in the same position of InGaN/GaN film were compared, the relationship of light and the defects was analyzed. It was identified that the big size V-defect and the small size V-defect as heat corrosion pit in film had no help to InGaN film material glow. Combined with SEM images and CL Mapping, part of In rich region was preliminary confirmed. The wave of light which made by fiat surface morphology and gully region area of InGaN/GaN film was also studied.