高Al含量AlGaN多层外延材料的应变与位错密度研究  

Research of Strain State and Dislocation Density in the Multiple AlGaN Epitaxial Layers with High Al Content

作　　者：游达[1] 王庆学[1] 汤英文[1] 龚海梅[1] 

机构地区：[1]传感技术国家重点实验室中国科学院上海技术物理所,上海200083

出　　处：《激光与红外》2005年第11期880-882,共3页Laser & Infrared

摘　　要：文中利用X射线三轴衍射测试手段对高A l(x≥0.45)含量p-i-n结构的A lxGa1-xN外延材料进行测试,并结合倒易空间图(RSM)和PV函数法对A lxGa1-xN外延材料进行评价。首先通过对RSM的定性分析,给出多层外延材料中不同A l组分A lxGa1-xN材料的应变状态和位错密度等信息,然后结合PV函数法拟合了从RSM中分离出的摇摆曲线,通过拟合过程准确地计算了多层结构中不同组分的A lxGa1-xN材料的纵向和横向应变量与螺位错密度,测试及计算结果都表明:多层p-i-n结构的A lxGa1-xN外延材料的应变与位错密度与单层结构相差较大,表明层与层之间的应变和位错相互作用对各层的应变的位错密度有重要的影响。The p-i-n multiple-layer AlxGa1-xN sample with high Al （ x 〉0.45 ） content was measured by the tripleaxis X-ray diffraction method. The RSM （ reciprocal space map） method and PV function were first combined to give more detailed information about the epitaxial AlxGa1-xN materials. The strain state and screw dislocation density of each layer of AlxGa1-xN epitaxial material were determined by RSM method. Then, the PV function was used to fit the rock curves separated from the RSM. At last, the strain and the screw dislocation density of each layer was accurately calculated. The calculated results show that the strain-state and the screw density of AlGa1-xN multiple-layered structure are so different with those of single-layer structure AlGa1-xN. The differences indicated that the interaction of the strain and the dislocation can affect those in each layer, consequendy.

关 键 词：ALGAN 倒易空间图 应变 PV函数 

分 类 号：TN304.2[电子电信—物理电子学] TN304.055