In this paper, to overcome the issues of high roughness and defect density in (001) β-Ga₂O₃ homoepitaxial films grown by MOCVD, a novel in-situ pulsed Al atom assisted growth method is proposed. Compared to films grown by conventional growth methods, the β-Ga₂O₃ epitaxial film grown using this method exhibited lower RMS roughness and a smaller FWHM of the (002) peak in the X-ray rocking curve. Additionally, oxygen vacancy defects within the film are significantly reduced, and Al incorporation is relatively limited without inducing lattice distortion. The width of serrations at the substrate-epitaxial layer interface is reduced from 70 nm to 17 nm, demonstrating improved interface flatness. The mechanism of pulsed Al atoms in optimizing homoepitaxial growth of (001) β-Ga₂O₃ is proposed, including their roles as preferential nucleation sites for Ga atoms, their inhibitory effects on Ga₂O formation and desorption, and the enhancement of atomic diffusion while minimizing parasitic side reactions. The phenomenon of epitaxial orientation rotation is observed, and a hypothesis is proposed regarding the causes of the difference in rotation angle and surface flatness. Additionally, Schottky barrier diodes (SBDs) are also fabricated to study the electrical properties of these epitaxial materials. The epitaxial layer obtained through the pulsed Al atom assisted growth method exhibited a breakdown field strength of 1.8 MV/cm. These results demonstrate that the pulsed Al atom assisted growth method may serve as a valuable reference for achieving high-quality (001) β-Ga₂O₃ epitaxial growth by the MOCVD method.

中文翻译：

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（001） MOCVD 原位脉冲 Al 原子辅助法生长的 β-Ga2O3 同质外延层


本文为克服 MOCVD 生长的 （001） β-Ga₂O₃ 同质外延膜粗糙度高和缺陷密度高的问题，提出了一种新型原位脉冲 Al 原子辅助生长方法。与通过常规生长方法生长的薄膜相比，使用这种方法生长的 β-Ga₂O₃ 外延膜表现出较低的 RMS 粗糙度和 X 射线摇摆曲线中 （002） 峰的较小 FWHM。此外，薄膜内的氧空位缺陷显着减少，并且 Al 掺入相对有限，而不会引起晶格畸变。衬底-外延层界面处的锯齿宽度从 70 nm 减少到 17 nm，表明界面平整度得到改善。提出了脉冲 Al 原子优化 （001） β-Ga₂O₃ 同轴生长的机制，包括它们作为 Ga 原子优先成核位点的作用，它们对 Ga₂O 形成和解吸的抑制作用，以及在最大限度地减少寄生副反应的同时增强原子扩散。观察到外延方向旋转的现象，并提出了关于旋转角度和表面平整度差异的原因的假设。此外，还制造了肖特基势垒二极管 （SBD） 来研究这些外延材料的电气特性。通过脉冲 Al 原子辅助生长方法获得的外延层表现出 1.8 MV/cm 的击穿场强。这些结果表明，脉冲 Al 原子辅助生长方法可作为通过 MOCVD 方法实现高质量 （001） β-Ga₂O₃ 外延生长的宝贵参考。