摘要
非极性a面AlN(a-AlN)能够从根本上解决极性AlN引起的量子限制斯塔克效应问题,是提升AlGaN发光器件效率的有效途径。但是,非极性AlN生长面临更大的挑战,目前难以实现低缺陷密度、高平整表面的非极性a-AlN。高温热处理是一种提高AlN质量的有效方法,但在热处理过程中,非极性a-AlN的表面形貌演变的物理机理尚不明确,直接影响了a-AlN表面改善与质量提升。本研究通过对a-AlN薄膜在不同条件下进行高温热处理,对样品的表面形貌演变过程进行了表征与分析,并结合第一性原理计算,揭示了高温热处理对非极性a-AlN表面的影响及其物理机理。结果表明,在高温热处理过程中Al、N原子更趋向于从a面与m面分解,而在c面吸附,使得a-AlN样品表面在高温热处理过程中出现了沿c轴方向的高取向性条纹原子台阶形貌,进而提高a-AlN材料质量。本研究为实现高质量非极性a-AlN材料及紫外发光器件提供了重要基础。
Nonpolar a-AlN is the fundamental method to eliminate quantum-confined Stark effect,and further improve the efficiency of AlGaN-based devices such as light-emitting diodes.However,it is hard to obtain high quality nonpolar a-AlN on heterogeneous substrates because the large and inhomogeneous mismatch between the heterogeneous substrate and the epitaxial layer.High temperature annealing is an effective and repeatable method to improve the quality of AlN templates.However,the physical mechanism is still not clear on how the high temperature annealing method effects the surface morphology of non-polar AlN,which affects the quality improvement of a-AlN.In this work,the surface evolution of the a-AlN with high temperature annealing has been investigated and the mechanism of how the thermal annealing effects on the surface evolution has been explored both by experiment and first-principles calculations.It is found that the Al/N atoms tend to decompose along a-/m-plane AlN and reabsorb along c-plane AlN,which result in the phenomenon that the area of ordered stripes along c-axis increases with higher annealing temperature or longer annealing time.The research will provide deeper understanding on the mechanism of the HTA effect on a-AlN,which will be benefit to the fabrication of a-AlN related devices.
作者
隋佳恩
贲建伟
臧行
蒋科
张山丽
郭冰亮
陈洋
石芝铭
贾玉萍
黎大兵
孙晓娟
SUI Jia-en;BEN Jian-wei;ZANG Hang;JIANG Ke;ZHANG Shan-li;GUO Bing-liang;CHEN Yang;SHI Zhi-ming;JIA Yu-ping;LI Da-bing;SUN Xiao-juan(State Key Laboratory of Luminescence and Applications,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Beijing NAURA Microelectronics Equipment,Beijing 100049,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2021年第6期810-817,共8页
Chinese Journal of Luminescence
基金
国家自然科学基金(61922078,61874118,62004127)资助项目。
关键词
a-AlN
高温热处理
表面形貌演变
结合能
a-AlN
high temperature annealing
surface morphology evolution
binding energy
