Abstract Gallium nitride substrates grown by the hydride vapor phase epitaxy (HVPE) method using a patterned growth process have been characterized by synchrotron monochromatic beam X-ray topography in the grazing incidence geometry. Images reveal a starkly heterogeneous distribution of dislocations with areas as large as 0.3 mm2 containing threading dislocation densities below 103 cm−2 in between a grid of strain centers with higher threading dislocation densities (>104 cm−2). Basal plane dislocation densities in these areas are as low as 104 cm−2. By comparing the recorded images of dislocations with ray tracing simulations of expected dislocations in GaN, the Burgers vectors of the dislocations have been determined. The distribution of threading screw/mixed dislocations (TSDs/TMDs), threading edge dislocations (TEDs) and basal plane dislocations (BPDs) is discussed with implications for fabrication of power devices.

中文翻译：

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用于功率器件开发的氮化镓衬底的 X 射线形貌表征

摘要 通过氢化物气相外延 (HVPE) 方法使用图案化生长工艺生长的氮化镓衬底已通过掠入射几何中的同步加速器单色光束 X 射线形貌进行表征。图像显示位错分布非常不均匀，面积大至 0.3 mm2，在应变中心网格之间包含低于 103 cm−2 的穿透位错密度，具有较高的穿透位错密度 (>104 cm−2)。这些区域的基面位错密度低至 104 cm-2。通过将记录的位错图像与 GaN 中预期位错的射线追踪模拟进行比较，已经确定了位错的伯格斯矢量。螺纹螺纹/混合位错（TSDs/TMDs）的分布，