We report on the properties of gallium oxide (Ga₂O₃) thin films deposited on c-plane sapphire substrates using radio frequency magnetron sputtering under various conditions. The parameters varied included the composition of the deposition gas, the substrate temperature, and postdeposition annealing temperature. The optical characteristics obtained by UV-VIS spectroscopy showed excellent transparency of 90%–95% for all the films obtained. The structural and compositional properties of the films were determined using x-ray diffraction and energy dispersive spectrometry measurements. The films deposited in Ar at 400 °C showed diffraction peaks at 18.6°, 37.2°, and 58.2°, which are attributed to diffraction peaks from $(\overline{2}01)$, $(\overline{4}02)$, and $(\overline{6}03)$ planes of β-Ga₂O₃. Postdeposition annealing in N₂ at 400–900 °C did not make any improvement in the crystalline quality of the films. The addition of tin in the films produced transparent films whose optical bandgaps decreased with increasing tin concentration in the films.

中文翻译：

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溅射沉积Ga2O3薄膜的微观结构和光学性质

我们报告了使用射频磁控溅射在各种条件下沉积在c面蓝宝石衬底上的氧化镓（Ga ₂ O ₃）薄膜的性能。改变的参数包括沉积气体的组成，衬底温度和沉积后退火温度。通过UV-VIS光谱学获得的光学特性显示，所有获得的薄膜具有90％–95％的极佳透明度。使用X射线衍射和能量色散光谱法测定膜的结构和组成性质。在400°C的Ar中沉积的薄膜在18.6°，37.2°和58.2°处显示出衍射峰，这归因于$（\overline{\mathrm{2个}}0\mathrm{1个}）$， $（\overline{4}0\mathrm{2个}）$， 和 $（\overline{6}03）$的平面β -Ga ₂ ö ₃。在N _2中在400–900°C下进行沉积后退火，并没有改善薄膜的晶体质量。薄膜中锡的添加产生了透明的薄膜，其光学带隙随薄膜中锡浓度的增加而降低。