Abstract Face-to-face annealed metalorganic vapor phase epitaxy (MOVPE)- grown AlN templates with sputtered AlN nucleation layers (FFA MOSp-AlN templates) were fabricated on vicinal sapphire substrates. The sputtered thin AlN layer supplies AlN seeds that are well aligned to the c-axis. The MOVPE growth with a relatively thick AlN enlarges crystal grains with a low concentration of impurities. Face-to-face annealing at high temperatures reduces the twist component of AlN films due to recrystallization, and AlN films with low threading dislocation densities are formed. The full width at half maximum (FWHM) of the (10-12) X-ray rocking curves (XRCs) of AlN templates decreased as the thickness of the MOVPE-grown AlN layer increased. The FWHMs for the (0002) and (10-12) XRCs of the 300-nm-thick AlN templates with an off-cut angle of 0.6° were 10 and 337 arcsec, respectively. The concentrations of O, Si, and C impurities in the FFA MOSp-AlN templates were lower than those in the face-to-face annealed sputtered AlN templates. Si doped Al0.7Ga0.3N films, which are typically used as n-type AlGaN layers for UVC LEDs, were grown on the FFA MOSp-AlN templates with various off-cut angles. The AlGaN films with smooth flat surfaces were obtained using the FFA MOSp-AlN template with larger off-cut angles due to the suppression of the large hillock formation

中文翻译：

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具有溅射成核层的相邻蓝宝石衬底上面对面退火 MOVPE 生长的 AlN 的晶体质量改善

摘要 面对面退火金属有机气相外延 (MOVPE) 生长的具有溅射 AlN 成核层的 AlN 模板（FFA MOSp-AlN 模板）在相邻的蓝宝石衬底上制造。溅射的薄 AlN 层提供与 c 轴良好对齐的 AlN 种子。具有相对厚的 AlN 的 MOVPE 生长扩大了具有低杂质浓度的晶粒。高温面对面退火降低了 AlN 薄膜由于再结晶而产生的扭曲分量，形成了具有低穿透位错密度的 AlN 薄膜。随着 MOVPE 生长的 AlN 层厚度的增加，AlN 模板的 (10-12) X 射线摇摆曲线 (XRC) 的半峰全宽 (FWHM) 减小。切角为 0 的 300 nm 厚 AlN 模板的 (0002) 和 (10-12) XRC 的 FWHM。6° 分别为 10 和 337 弧秒。FFA MOSp-AlN 模板中 O、Si 和 C 杂质的浓度低于面对面退火溅射 AlN 模板中的浓度。Si掺杂的Al0.7Ga0.3N薄膜，通常用作UVC LED的n型AlGaN层，在FFA MOSp-AlN模板上以不同的切角生长。使用FFA MOSp-AlN模板获得具有光滑平坦表面的AlGaN薄膜，由于抑制了大小丘的形成，具有更大的切角