The in-situ parasitic microstructure interface and defect formation mechanism in (010) β-Ga_(2)O_(3) epitaxial film via MOCVD  

MOCVD外延的(010)β-Ga_(2)O_(3)中原位寄生微结构界面与缺陷形成机制研究

作　　者：Xianqiang Song Yunlong He Zhan Wang Xiaoli Lu Jing Sun Ying Zhou Yang Liu Jiatong Fan Xiaoning He Xuefeng Zheng Xiaohua Ma Yue Hao 宋先强;何云龙;王湛;陆小力;孙静;周颖;刘洋;范佳桐;何晓宁;郑雪峰;马晓华;郝跃(State Key Laboratory of Wide-Bandgap Semiconductor Devices and Integrated Technology,National Engineering Research Center of Wide Band-Gap Semiconductor,School of Microelectronics,Xidian University,Xi’an 710071,China;School of Electronic Engineering,Xi’an University of Posts&Telecommunications,Xi’an 710121,China;Guangzhou Institute of Technology,Xidian University,Guangzhou 510555,China;Shaanxi Semiconductor Industry Association,Xi’an 710065,China)

机构地区：[1]State Key Laboratory of Wide-Bandgap Semiconductor Devices and Integrated Technology,National Engineering Research Center of Wide Band-Gap Semiconductor,School of Microelectronics,Xidian University,Xi’an 710071,China [2]School of Electronic Engineering,Xi’an University of Posts&Telecommunications,Xi’an 710121,China [3]Guangzhou Institute of Technology,Xidian University,Guangzhou 510555,China [4]Shaanxi Semiconductor Industry Association,Xi’an 710065,China

出　　处：《Science China Materials》2025年第2期515-522,共8页中国科学(材料科学)(英文版)

基　　金：supported by the National Natural Science Foundation of China (62474133, U2241220 and 62304172);the Opening Project of State Key Laboratory of Wide Bandgap Semiconductor Devices and Integrated Technology (2413S111);the Fundamental Research Funds for the Central Universities of China (QTZX23019 and ZDRC2002);in part by Guangdong Basic and Applied Basic Research Foundation (2021A1515110020)。

摘　　要：In this study, a typical hillock surface defect wasdiscovered in (010) β-Ga_(2)O_(3) thin films grown by metal-organicchemical vapor deposition (MOCVD), and the morphologyand structure were systematically investigated. The observeddefects exhibit a polygonal shape with a ridge-like hillockalong the [001] direction. Transmission electron microscopy(TEM) microanalysis reveals that polygonal hillock defects arecomposed of twin grains forming an inverted pyramid shapeembedded in the epitaxial layer, which exhibits twofold rotational symmetry along the [100] crystal direction. Theboundary between the defective and perfect lattices appearsband-like, characterized by complex faults, with structuralrelationships between the twin region and the matrix identified as [001]matrix||[010]Defect and {−310}matrix||{−201}Defect. Theorigin of surface defects in the (010) β-Ga_(2)O_(3) homoepitaxiallayers could be attributed not only to the extent of substratedefects but also to epitaxial process conditions. The definitiveexplanation is the localized aggregation of gallium atoms/oxygen vacancies during the growth process, as evidenced byenergy-dispersive X-ray (EDX) analysis and optimized experiments. This work provides brand-new perspectives intothe study of defects in β-Ga_(2)O_(3) epitaxial films, which furtheradvances the application of Ga_(2)O_(3) materials in power devicetechnologies.在本文中,我们在MOCVD外延生长的(010)β-Ga_(2)O_(3)薄膜中的界面缺陷形貌结构及形成机理进行了系统分析.通过观测发现了一种丘状表面缺陷,该缺陷呈多边形,并沿[001]方向呈现出脊状凸起.透射电子显微(TEM)微观分析表明,多边形丘状缺陷由孪晶组成,呈倒金字塔形嵌入外延层中,并沿[100]晶向具有二重旋转对称性.缺陷晶格与完美晶格之间的边界呈带状,伴随复杂的位错结构,其孪晶区与基体的结构关系被确定为[001]Matrix‖[010]Defect和{-310}Matrix‖{-201}Defect.(010)β-Ga_(2)O_(3)同质外延层中的表面缺陷成因不仅与衬底缺陷有关,还受到外延工艺条件的影响.最后,我们通过EDX分析和实验证实,缺陷的形成可能主要归因于生长过程中镓原子和/或氧空位的局部聚集.该研究为β-Ga_(2)O_(3)外延薄膜中的缺陷机制提供了全新的视角,并为Ga_(2)O_(3)材料外延技术改进以及功率器件性能提升奠定了重要基础.

关 键 词：β-Ga_(2)O_(3) MOCVD surface defect 

分 类 号：TB383.2[一般工业技术—材料科学与工程]