Origins of threading dislocations in GaN epitaxial layers grown on sapphire by metalorganic chemical vapor deposition
Origins of threading dislocations in GaN epitaxial layers grown on sapphire by metalorganic chemical vapor deposition
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DOI：
10.1063/1.1352699
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发表时间：
2001-03
影响因子：
4
通讯作者：
V. Narayanan;K. Lorenz;Wook Kim;S. Mahajan
中科院分区：
文献类型：
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作者：
V. Narayanan;K. Lorenz;Wook Kim;S. Mahajan
通过透射电镜观察低温氮化镓成核层（NLs）上高温氮化镓生长的不同阶段，研究了（0001）蓝宝石上生长的氮化镓外延层中螺纹位错（TDs）的成因。结果表明，在HT生长20 s后，GaN岛的TDs已被清除。生长75 s和120s后，大部分岛屿为纯螺旋型（c型）和纯边缘型（a型）td，夹杂有混合型（c+a型）td。大部分td起源于NLs内的断裂区域。td向岛屿顶面移动（c型）或向岛屿侧面移动（a， c+a型）。HT - GaN岛的合并不产生a型、c型和c+a型TDs。生长240 s后，大部分td主要为一种类型，可能是由位于断裂带内的肖克利部分解离形成的基面位错（BP）的爬升和滑动所致。BP脱位也被观察到附在侧fa…
The origins of threading dislocations (TDs) in GaN epitaxial layers grown on (0001) sapphire have been investigated by examining different stages of high-temperature (HT) GaN growth on low-temperature GaN nucleation layers (NLs) by transmission electron microscopy. Results indicate that after 20 s of HT growth, GaN islands were free of TDs. After 75 and 120 s of growth, most of the islands contained pure screw (c type) and pure edge (a type) TDs with an interspersion of mixed (c+a type) TDs. Most of the TDs originated from faulted regions located within NLs. TDs move toward the island top surface (c type) or curve toward island side facets (a, c+a type). Coalescence of HT GaN islands did not give rise to either a, c, or c+a type TDs. After 240 s of growth, most TDs were predominantly of a type and could result from climb and glide of basal plane (BP) dislocations that form by the dissociation of Shockley partials located within the faulted regions. BP dislocations are also observed attached to the side fa...