金属调制分子束外延生长氮化铝薄膜  

AlN Films Fabricated by Molecular Beam Epitaxy with Metal Modulation

作　　者：刘欢 邵鹏飞 陈松林 周辉 李思琦 陶涛[1] 谢自力[1] 刘斌[1] 陈敦军[1] 郑有炓[1] 张荣[1] 王科 LIU Huan;SHAO Pengfei;CHEN Songlin;ZHOU Hui;LI Siqi;TAO Tao;XIE Zili;LIU Bin;CHEN Dunjun;ZHENG Youdou;ZHANG Rong;WANG Ke(School of Electronic Science and Engineering,Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学电子科学与工程学院,南京210023

出　　处：《人工晶体学报》2023年第5期878-885,共8页Journal of Synthetic Crystals

基　　金：国家自然科学基金(61974065);国家重点研发计划(2022YFB3605602);江苏省重点研发计划(BE2020004-3,BE2021026);江苏省特聘教授项目。

摘　　要：本文利用等离子体辅助分子束外延(PA-MBE)系统,对常规连续外延生长和金属调制外延(MME)生长AlN薄膜进行研究。研究发现:常规连续外延方法生长模式不易控制,容易出现过度富Al和富N模式生长,而且微富Al模式生长还会出现一些凹坑,表面形貌较粗糙;然而利用MME方法生长AlN薄膜,通过精准调控Al源和N源快门打开、关闭时间,可以获得形貌较好的AlN薄膜。通过调整优化获得的MME方案为:首先Al源快门打开30 s,然后Al源和N源快门打开60 s,最后单独打开N源快门72 s;单一周期内,Al源快门打开时间与N源快门打开时间比例为0.7。以上述方案为一个周期进行循环生长40个周期,可获得粗糙度低至0.3 nm(2μm×2μm),几乎无凹坑的AlN薄膜。In this paper,conventional continuous epitaxial growth and metal modulated epitaxial(MME)growth of AlN were investigated with the plasma-assisted molecular beam epitaxy(PA-MBE)system.It is difficult to control the growth mode of the conventional continuous epitaxial growth method,in which excessive Al-rich and N-rich growth modes easily occur,and also a slightly Al-rich growth mode is accompanied by the appearance of some pits,leading to rough surface morphology.However,the growth mode of AlN films is easier to control by MME method,by which AlN films with good morphology can be fabricated by adjusting the supply time of Al and N sources.The optimized MME solution is proposed as follows:firstly,opening the Al source shutter for 30 s,then opening the Al and N source shutters for 60 s,and finally opening the N source shutter alone for 72 s,the ratio of Al source shutter opening time to N source shutter opening time of a single cycle is 0.7.Almost pits-free AlN films with a low roughness of 0.3 nm(2μm×2μm)are fabricated after 40 cycles.

关 键 词：金属调制 分子束外延 外延生长 氮化铝 粗糙度 

分 类 号：O782[理学—晶体学] O484