In this paper, the surface state of the single-crystalline AlN template's impact on the epitaxial growth of gallium nitride (GaN) was studied. Subsequently, Schottky barrier devices were fabricated and analyzed. The results indicate that surface states subjected to different treatments exhibit varying epitaxial growth modes at the initial nucleation stage, which have a correlated effect on surface topography, crystalline quality, strain and other material characteristics of the epitaxial GaN. Higher surface energy leads to a reduction in screw dislocation of GaN material, but has less influence on edge dislocation. Single-crystalline AlN templates with higher surface energy are more likely to exhibit Stranski-Krastanow and Frank-van der Merwe growth model and achieve high-quality epitaxial materials. Schottky devices prepared using GaN material with lower screw dislocation density exhibit lower reverse leakage current. First-principles simulation analysis revealed that the migration barrier of gallium and nitrogen atoms on the surface can be overcome with the larger surface energy of single-crystalline AlN template. This facilitates their migration on the surface, resulting in higher quality material epitaxy. The conclusions of this work provide insights for quality control of epitaxial GaN materials on single-crystalline AlN templates, as well as for studying device leakage in the backend of the device fabrication process, or similar homogeneous compound semiconductor heteroepitaxy studies.

中文翻译：

---

从 GaN 结晶度到器件性能：成核模式与单晶 AlN 模板的表面能


本文研究了单晶AlN模板的表面态对氮化镓(GaN)外延生长的影响。随后，制作并分析了肖特基势垒器件。结果表明，经过不同处理的表面态在初始成核阶段表现出不同的外延生长模式，这对外延GaN的表面形貌、晶体质量、应变和其他材料特性具有相关影响。较高的表面能导致GaN材料的螺旋位错减少，但对刃位错的影响较小。具有较高表面能的单晶AlN模板更有可能表现出Stranski-Krastanow和Frank-van der Merwe生长模型并获得高质量的外延材料。使用具有较低螺位错密度的GaN材料制备的肖特基器件表现出较低的反向漏电流。第一性原理模拟分析表明，单晶AlN模板具有较大的表面能，可以克服表面镓和氮原子的迁移势垒。这有利于它们在表面上的迁移，从而产生更高质量的材料外延。这项工作的结论为单晶 AlN 模板上外延 GaN 材料的质量控制，以及研究器件制造过程后端的器件泄漏或类似的同质化合物半导体异质外延研究提供了见解。