【摘要】 利用LP-MOCVD技术,采用两步生长法在Ga As(100)单晶衬底上外延生长InxGa1-xAs材料。通过扫描电子显微镜(SEM)与原子力显微镜(AFM)观察了缓冲层厚度对外延层表面形貌、表面粗糙度的影响;利用X射线衍射(XRD)分析了缓冲层厚度对外延层结晶质量的影响;利用拉曼光谱分析了缓冲层厚度对外延层材料合金有序度的影响;通过透射电子显微镜(TEM)观察了外延层材料位错的分布状态,计算了外延层的位错密度。实验结果表明,两步生长法生长的InxGa1-xAs/Ga As异质结材料的缓冲层厚度存在一个最优值。更多还原

【Abstract】 InxGa1-xAs was deposited on( 100) Ga As substrate by MOCVD with the two-step growth. The effects of buffer layer thickness on the surface morphology,crystalline quality,and alloy order degree of the epilayer were analyzed by SEM,AFM,XRD,and Raman spectroscopy,respectively. The distribution of dislocations in epilayer was observed by TEM and the dislocation density was calculated. The experiment results show that the buffer layer thickness of InxGa1-xAs heterostructure has the optimal value.更多还原