A third generation mist chemical vapor deposition (3rd G mist CVD) system was used to grow six single-layer and two heterostructure α-(AlxGa1−x)2O3 buffers on c-plane sapphire substrates for the subsequent deposition of conductive Sn-doped α-Ga2O3 (Sn:α-Ga2O3) thin films. In the six single-layer buffers, the Al contents x increased from 0 to 0.66. The two heterostructure buffers consisted of six ∼20-nm- and ∼100-nm-thick layers laying on top of each other. The 3rd G mist CVD system enabled the growth of these complicated multi-layer heterostructures in a single run, while mono-crystallinity was still maintained in all grown layers. Strain was observed in the 20-nm heterostructure, while the layers in the 100-nm heterostructure almost fully relaxed and the Vegard’s law was followed even when the α-(AlxGa1−x)2O3 layers were stacked on each other. Transmission electron microscopy analyses show that the dislocation densities remained high in the order of 1010 cm−2 despite the employment of the buffers. PtOx and AgOx Schottky diodes (SDs) were fabricated on the Sn:α-Ga2O3 films. The barrier height vs ideality factor plots could be fitted by linear dependences, indicating that the large ideality factors observed in α-Ga2O3 SDs could be explained by the inhomogeneity of the SDs. The extrapolation of the dependences for the PtOx and AgOx SDs yielded homogeneous Schottky barrier heights of ∼1.60 eV and 1.62 eV, respectively, suggesting that the Fermi level was pinned at the Ec − 1.6 eV level. The Sn:α-Ga2O3 film grown on the strained 20-nm heterostructure buffer showed best characteristics overall.

中文翻译：

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α-(AlxGa1-x)2O3 单层和异质结构缓冲剂，用于通过雾化学气相沉积生长导电 Sn 掺杂的 α-Ga2O3 薄膜

第三代雾化学气相沉积（3rd G雾CVD）系统用于在c面蓝宝石衬底上生长六个单层和两个异质结构α-（AlxGa1-x）2O3缓冲液，用于随后沉积导电Sn掺杂的α -Ga2O3 (Sn:α-Ga2O3) 薄膜。在六个单层缓冲液中，Al 含量 x 从 0 增加到 0.66。两个异质结构缓冲层由六个~20-nm 和~100-nm 厚的层组成，彼此叠加。3rd G 雾状 CVD 系统能够在一次运行中生长这些复杂的多层异质结构，同时在所有生长层中仍保持单晶。在 20-nm 异质结构中观察到应变，而 100-nm 异质结构中的层几乎完全松弛，即使当 α-(AlxGa1-x)2O3 层相互堆叠时也遵循 Vegard 定律。透射电子显微镜分析表明，尽管使用了缓冲液，位错密度仍保持在 1010 cm-2 的数量级。PtOx 和 AgOx 肖特基二极管 (SD) 制作在 Sn:α-Ga2O3 薄膜上。势垒高度与理想因子图可以通过线性相关性拟合，表明在 α-Ga2O3 SDs 中观察到的大理想因子可以用 SDs 的不均匀性来解释。对 PtOx 和 AgOx SD 的依赖性的外推分别产生了约 1.60 eV 和 1.62 eV 的均匀肖特基势垒高度，表明费米能级被固定在 Ec - 1.6 eV 能级。Sn:α-Ga2O3 薄膜生长在应变的 20-nm 异质结构缓冲层上，整体表现出最佳特性。