LP-MOCVD两步生长法制备的InAs_(0.9)Sb_(0.1)/GaAs  

InAs_(0.9)Sb_(0.1)/GaAs Prepared by a Two-step Growth Method with LP-MOCVD

作　　者：谢建春[1] 缪国庆[1] 金亿鑫[1] 张铁民[1] 宋航[1] 蒋红[1] 刘乃康[1] 李志明[1] 

机构地区：[1]中国科学院激发态物理重点实验室

出　　处：《发光学报》2007年第2期246-250,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目(50372067)

摘　　要：利用LP-MOCVD技术,采用两步生长法,在(100)GaAs单晶衬底上生长高质量的InAs0.9Sb0.1。用扫描电镜、X射线单晶衍射、Hall测量以及Raman光谱等方法对材料进行了表征。分析了缓冲层和外延层生长温度对外延层表面形貌的影响。获得了表面光亮,室温载流子浓度为1.9×1017cm-3和迁移率为6214cm2/V.s的InAs0.9Sb0.1。在室温Raman光谱中观察到InAs0.9Sb0.1中InAs(LO)的233cm-1和InSb(LO)的187cm-1两种光学声子行为。The two-step growth method including growing the buffer layer on the substrate at a low-temperature and followed by growing the epitaxial layer at a high-temperature, was applied to grow high-quality InAs0.9Sb0.1 on （100） GaAs substrate by LP-MOCVD. The thickness of the buffer layer and the epitaxial layer are 30 nm and 0.7 μm, respectively. The composition and crystalline quality of InAsSb were examined by means of X-ray diffraction technique, the surface morphology of the epitaxial layers was observed by scanning electron microscopy （SEM） and the electrical property of samples was measured by Hall measurements using the Van Der Pauw method. The optical properties were examined by Raman scattering measurements. The effect of the growth temperatures of both the buffer layer and the epitaxial layer on the surface morphology of the epitaxial layer has been studied. The surface morphology was found to be essentially dependent on the growth temperatures of both the buffer layer and the epitaxial layer. Generally speaking, growing a buf- fer layer between the substrate and the epitaxial layer can decrease effectively the misfit dislocations generated by the lattice mismatch between them. The experiment shows that the epitaxial layer has poor crystalline quality if the growth temperature of the buffer layer is higher. A possible explanation is the buffer lattice grown at higher temperature would become too perfect to relax stress. As a result, the misfit dislocation was extend to the epitaxial layer and formed the poor surface morphology, but the buffer layer grown at the lower temperature can decrease effectively the misfit dislocations generated by the lattice mismatch between the substrate layer and the epitaxial layer. Finally, the optimum growth temperature of the buffer layer was range from 430 ℃ to 450 ℃. In the other side, the surface morphology would become poor for the epitaxial layer at higher growth temperature. The optimum growth temperature of the epitaxial layer should be selected between

关 键 词：金属有机化学气相沉积 INASSB 两步生长法 GAAS 

分 类 号：TN304.55[电子电信—物理电子学]