基于蓝宝石衬底的GaN/h-BN弱耦合外延体系界面机理研究

基于二维氮化硼（h-BN）的氮化镓（GaN）基半导体外延技术有望制备出失配应力弛豫、易与衬底分离的高质量外延结构，在可穿戴电子、新型显示等领域具有重要应用价值。深化GaN/h-BN外延体系的界面机理研究，突破“h-BN上GaN键合机制及其对上层GaN的作用机理”这一关键科学技术问题，有助于完善外延工艺，提高材料质量，推动新型器件研制工作。针对上述关键问题，本项目拟基于商用蓝宝石衬底开展GaN/h-BN外延体系界面机理研究工作，通过实验测量结合理论计算的方式阐明h-BN上GaN的成核成键机制及极性调控机制，掌握GaN/h-BN界面弱耦合作用的形成、调控机制及对上层GaN位错密度的作用形式，建立h-BN上GaN外延层晶格极性、位错密度的界面调控技术，在h-BN/Al2O3衬底上实现高质量GaN外延层的可控制备，为新型氮化物半导体器件的应用探索工作提供材料支持与技术指导。

Two-dimensional hexagonal boron nitride (h-BN) assisted epitaxy of gallium nitride (GaN)-based semiconductors is promising to fabricate high-quality epilayers with relaxed mismatch stress and high separability from substrates, having important applications in wearable electronic devices, smart displays and many other fields. In order to improve the epitaxial process, enhance the quality of epilayers and accelerate the development of novel devices, it is necessary to systematically explore the interface mechanism of the GaN/h-BN epitaxial system and resolve the key issue of "GaN bonding mechanism on h-BN and its regulation on the upper GaN". Therefore, this proposal is expected to illustrate the core interface mechanism of GaN/h-BN epitaxial system based on commercial sapphire substrates. Firstly, with experimental measurements and theoretical calculations, we will investigate the interface bonding mechanism and polarity regulation mechanism of GaN layer grown on h-BN. And then, we will explore the formation and regulation mechanism of weak interface coupling and its effect on the dislocation density of the upper grown GaN layers. Finally, we would like to establish the technology to control lattice polarity and reduce dislocation density of the GaN epilayer grown on h-BN, and achieve high-quality GaN epilayers with different lattice polarities. If horned to be approved, this proposal will promote the application and exploration of novel devices fabricated with III-nitride semiconductors.