Defect structure of metal‐organic chemical vapor deposition‐grown epitaxial (0001) GaN/Al2O3
Defect structure of metal‐organic chemical vapor deposition‐grown epitaxial (0001) GaN/Al2O3
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DOI：
10.1063/1.363264
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发表时间：
1996-09
影响因子：
3.2
通讯作者：
Xinru Wu;L. M. Brown;D. Kapolnek;S. Keller;B. Keller;S. Denbaars;J. Speck
中科院分区：
文献类型：
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作者：
Xinru Wu;L. M. Brown;D. Kapolnek;S. Keller;B. Keller;S. Denbaars;J. Speck
利用透射电子显微镜研究了两步金属有机化学气相沉积法生长的GaN/Al 2 O3（0001）外延层的缺陷结构。通过衍射对比、高分辨率成像和会聚束衍射分析了缺陷结构，包括穿透位错、部分位错边界层错和反转畴。GaN膜生长在600 °C下以标称20 nm成核层开始。随后在1080 °C下进行高温生长。薄膜的近界面区域由立方和六方GaN的混合物组成，其特征在于由Shockley和Frank部分位错界定的高密度堆垛层错。近界面区域显示出高密度的反转域。厚度超过10.5 μm时，薄膜由孤立的纯刃位错、混合位错或纯螺位错组成，总密度为10.7 ×108 cm−2。螺纹脱位的减少.
Defect structures were investigated by transmission electron microscopy for GaN/Al2O3 (0001) epilayers grown by metal‐organic chemical vapor deposition using a two‐step process. The defect structures, including threading dislocations, partial dislocation bounding stacking faults, and inversion domains, were analyzed by diffraction contrast, high‐resolution imaging, and convergent beam diffraction. GaN film growth was initiated at 600 °C with a nominal 20 nm nucleation layer. This was followed by high‐temperature growth at 1080 °C. The near‐interfacial region of the films consists of a mixture of cubic and hexagonal GaN, which is characterized by a high density of stacking faults bounded by Shockley and Frank partial dislocations. The near‐interfacial region shows a high density of inversion domains. Above ∼0.5 μm thickness, the film consists of isolated threading dislocations of either pure edge, mixed, or pure screw character with a total density of ∼7×108 cm−2. The threading dislocation reduction in the...