The Roles of Threading Dislocations on Electrical Properties of AlGaN/GaN Heterostructure Grown by MBE
The Roles of Threading Dislocations on Electrical Properties of AlGaN/GaN Heterostructure Grown by MBE
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DOI：
10.1149/1.3392365
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发表时间：
2010-01-01
影响因子：
3.9
通讯作者：
Lin, Kung-Liang
中科院分区：
文献类型：
--
作者：
Wong, Yuen-Yee;Chang, Edward Yi;Lin, Kung-Liang
采用等离子体辅助分子束外延（MBE）生长AlGaN/GaN异质结，研究了不同类型的穿透位错（TD）对AlGaN/GaN异质结电学性能的影响。制备了具有不同缺陷结构和密度的样品，并对同一样品进行了测量，以研究各种TD的相关行为。从霍尔测量结果来看，二维电子气通道中的电子迁移率主要由刃型位错控制，刃型位错在材料中占主导地位。沟道边缘的TD在沟道内起到库仑散射中心的作用，降低了载流子迁移率，增加了沟道电阻。在决定肖特基势垒二极管的反向偏置漏电流方面，螺纹型TD比边缘型TD起着更重要的作用。对于边缘TD密度较高的样品，沟道中自由载流子密度的降低对漏电流的影响较小，但作为电流泄漏路径的螺旋TD对AlGaN/GaN结构的反向偏置漏电流的影响更大。(C)2010年电化学学会。[DOI：10.1149/1.3392365]保留所有权利。
The role played by different types of threading dislocations (TDs) on the electrical properties of AlGaN/GaN heterostructure grown by plasma-assisted molecular beam epitaxy (MBE) was investigated. Samples with different defect structures and densities were prepared and measurements were taken from the same sample to study the correlative behavior of various TDs. From the Hall measurement, the electron mobility in two-dimensional electron gas channel was mainly controlled by the edge dislocation, which has a dominant amount in the material. The edge TDs acted as Coulomb scattering centers inside the channel and reduces the carrier mobility and increased its resistance. Screw TDs played a much significant role than edge TDs in determining the reverse-bias leakage current of Schottky barrier diodes. Leakage current is affected slightly by the reduction of free carrier density in the channel for samples with a higher edge TD density, but screw TD, which acted as the current leakage path, was more deleterious to the reverse-bias leakage current of AlGaN/GaN structure. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3392365] All rights reserved.