摘要
随着氮化镓(GaN)在高功率领域的广泛应用,GaN基器件的散热性能成为了制约其功率密度的主要因素,因此开辟新的热管理方案至关重要。具有高热导率的金刚石衬底可以用于改善GaN器件的散热问题。然而,由于金刚石和GaN之间的天然晶格失配,在金刚石衬底上GaN的直接外延仍然是一个难以克服的问题。本工作以二维材料/Al组分渐变的AlGaN异质结作为衬底与外延层之间的成核层,在多晶金刚石衬底上实现了单晶GaN薄膜的范德瓦耳斯外延。其中,二维材料可以有效屏蔽掉衬底与外延层晶格不匹配带来的不良影响,而Al组分渐变的AlGaN缓冲层结构可实现Ga原子和N原子的有序迁移,进而精确地控制GaN薄膜的生长。本工作为异质衬底上高质量生长氮化物提供新思路。实验结果表明,成核层的引入有效地消除晶格失配的影响,从而打破了金刚石衬底上难以直接外延单晶GaN薄膜的瓶颈。本工作为GaN基器件的功率密度的进一步提升提供了基础。
With the widespread application of gallium nitride(GaN)in the high-power field,the heat dissipation of GaN based devices has become the main factor restricting the power density.Therefore,it is crucial to develop novel thermal management solutions.Diamond substrates with high thermal conductivity can be used to improve the heat dissipation of GaN devices.However,due to the natural lattice mismatch between diamond and GaN,the direct epitaxy of GaN on diamond substrates remains an insurmountable problem.This work achieved van der Waals epitaxy of single crystal GaN films on polycrystalline diamond substrates using a two-dimensional material/Al gradient AlGaN heterostructure as the nucleation layer between the substrate and the epitaxial layer.Among them,two-dimensional materials can effectively shield against the adverse effects caused by lattice mismatch between the substrate and epitaxial layer,while the Al component gradient AlGaN buffer layer can achieve orderly migration of Ga and N atoms,thereby accurately controlling the growth of GaN thin films.This work provides a novel approach for high-quality growth of nitrides on heterogeneous substrates.The experimental results indicate that the introduction of nucleation layers effectively eliminates the impact of lattice mismatch,thereby breaking the bottleneck of the difficulty in directly epitaxial single crystal GaN films on diamond substrates.This work provides a foundation for further improving the power density of GaN based devices.
作者
白玲
宁静
张进成
王东
王博宇
武海迪
赵江林
陶然
李忠辉
BAI Ling;NING Jing;ZHANG Jincheng;WANG Dong;WANG Boyu;WU Haidi;ZHAO Jianglin;TAO Ran;LI Zhonghui(The State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology,Xidian University,Xi’an 710071,China;Shaanxi Joint Key Laboratory of Graphene,Xidian University,Xi’an 710071,China;Xidian-Wuhu Research Institute,Wuhu 241000,China;CETC Key Laboratory of Carbon-Based Electronics,Nanjing Electronic Devices Institue,Nanjing 210016,China)
出处
《人工晶体学报》
CAS
北大核心
2023年第5期901-908,共8页
Journal of Synthetic Crystals
基金
国家自然科学基金(62274134)
国家重点R&D项目(2021YFA0716400)
国家杰出青年科学基金(61925404)
芜湖、西安电子科技大学产学研合作专项基金(XWYCXY-012021005)
国家重点科技专项(2009ZYHW0015):中央大学基础研究基金(JBF201101)
中央高校基本科研业务费专项资金(QTZX23052)。
关键词
GAN
金刚石
范德瓦耳斯外延生长
高散热
Al组分渐变
二维材料
GaN
diamond
van der Waals epitaxial growth
high heat dissipation
Al component gradient
two-dimensional material
