摘要
通过对常压MOCVD工艺下制备的GaN/A l2O3两种样品的X射线衍射分析,利用不同的掠入射角及倾斜ω扫描,精确测量了GaN薄膜的晶体结构和位错密度,据此提出了一种表征薄膜纵向位错密度的新方法。结果表明实验制备的GaN薄膜具有相当一致的c轴取向,对称衍射(002)面ω扫描半峰宽分别为229.8arcsec、225.7 arcsec;同时,根据倾斜对称ω扫描半峰宽分析认为样品A、B的位错密度分别约为4.0801×108/cm2,5.8724×108/cm2,其样品A的位错密度小于样品B,但PL谱给出样品A的发光效率低于样品B;而根据不同的掠入射ω扫描推断出样品A的位错密度大于样品B,与相应的发光性能吻合。
High -resolution X- ray diffraction was used to analyze the GaN layers grown on sapphire by metal -organic chemical vapor deposition （MOCVD）. The crystal structures and dislocation densities were determined by to - scans of the different grazing incidence angle and skew diffraction. A new X - ray diffraction method for measuring longitudinal dislocation density of GaN thin film was proposed. The full - width at half- maximum （FWHM） of the （002） scanning curve of the sample are respectively 229.8 arcsec ,225.7 arcsec, indicating that the GaN films are strongly c - oriented. The samples show respectively threading dislocation densities of 4. 0801 × 10^8/cm^2 ,5. 8724 × 10^8/cm^2, as extracted from X - ray to - scans in skew geometry. The dislocation densities of sample A are lower than that of sample B, which are inconsistent with luminescence results, while the dislocation densities deduced from grazing- incidence X -ray diffraction are consistent with luminescence results.
出处
《功能材料与器件学报》
EI
CAS
CSCD
北大核心
2006年第6期524-528,共5页
Journal of Functional Materials and Devices
基金
教育部高等学校骨干教师资助计划资助项目(No.GG-430-11902-1010)
关键词
GAN
高分辨X射线衍射
位错密度
掠入射
GaN
high resolution X - ray diffraction
threading dislocation
grazing - incidence X - ray diffraction
