分子束外延高Al组分AlGaN薄膜及Si掺杂研究

人工晶体学报 ›› 2023, Vol. 52 ›› Issue (5): 783-790.

分子束外延高Al组分AlGaN薄膜及Si掺杂研究

梁潇, 李思琦, 王中伟, 邵鹏飞, 陈松林, 陶涛, 谢自力, 刘斌, 陈敦军, 郑有炓, 张荣, 王科

南京大学电子科学与工程学院,南京 210023

收稿日期:2023-03-13 出版日期:2023-05-15 发布日期:2023-06-05
通信作者: 王科,博士,教授。E-mail:kewang@nju.edu.cn
作者简介:梁潇(1998—),男,湖北省人,硕士研究生。E-mail:mg21230029@smail.nju.edu.cn
基金资助:
国家重点研发计划(2022YFB3605602);国家自然科学基金(61974065);江苏省重点研发计划(BE2020004-3,BE2021026);江苏省特聘教授项目

Study on Molecular Beam Epitaxy of High Al Content AlGaN Thin Films and Si Doping

LIANG Xiao, LI Siqi, WANG Zhongwei, SHAO Pengfei, CHEN Songlin, 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

Received:2023-03-13 Online:2023-05-15 Published:2023-06-05

摘要/Abstract

摘要： 实现电学性能优良的高Al组分AlGaN外延层是制备深紫外光电器件最重要的环节之一。本工作利用分子束外延(MBE)技术,基于周期热脱附的生长方式,通过改变Al源供应量调控Al组分,并用Si进行n型掺杂,在AlN/蓝宝石衬底上得到了系列高Al组分的Si-Al_xGa_1-xN外延层(x＞0.60)。对外延层相关物理性质进行了表征测试,结果表明,外延层Al组分与生长过程中Al束流大小呈现线性关系,这为制备精确Al组分的AlGaN外延层奠定了基础。AFM结果表明,高Al组分AlGaN外延层的表面形貌强烈依赖于Ga的供应量,在生长过程中提高Ga束流可以显著降低外延层的粗糙度。基于范德堡法测量Si-AlGaN外延层电学性能,证实其载流子特性良好,其中 Al组分为0.93的样品室温下自由电子浓度、电子迁移率和电阻率分别达到了8.9×10¹⁸ cm^-3和3.8 cm²·V^-1·s^-1和0.18 Ω·cm。

关键词: 高Al组分AlGaN, 分子束外延, Si掺杂, 载流子特性, 周期热脱附

Abstract: Achieving AlGaN epitaxial layer with high Al content and excellent electrical properties is one of the most important aspects in the preparation of deep ultraviolet optoelectronic devices. In this work, a series of Si-Al_xGa_1-xN epitaxial layers with high Al content (x＞0.60) were obtained on AlN/sapphire substrates using molecular beam epitaxy (MBE) system, based on the growth method of periodic thermal desorption. Al content was modulated by changing the size of Al source supply, and n-type doping was realized with Si. The physical properties of the epitaxial layers were characterized. The results show that: Al content of the epitaxial layers shows a linear relationship with the Al flux size, which lays the foundation for the growth of AlGaN epitaxial layers with precise content. The AFM measurements reflect that the surface morphology of the AlGaN epitaxial layers strongly depend on the Ga supply. The electrical properties of Si-AlGaN epitaxial layers were measured based on the Vanderbilt method, and the good performance was confirmed. The free electron concentration, electron mobility and resistivity of the sample with Al content of 0.93 reach 8.9×10¹⁸ cm^-3, 3.8 cm²·V^-1·s^-1 and 0.18 Ω·cm respectively at room temperature.

Key words: high Al-content AlGaN, molecular beam epitaxy, Si doping, carrier property, periodic thermal desorption

中图分类号:

梁潇, 李思琦, 王中伟, 邵鹏飞, 陈松林, 陶涛, 谢自力, 刘斌, 陈敦军, 郑有炓, 张荣, 王科. 分子束外延高Al组分AlGaN薄膜及Si掺杂研究[J]. 人工晶体学报, 2023, 52(5): 783-790.

LIANG Xiao, LI Siqi, WANG Zhongwei, SHAO Pengfei, CHEN Songlin, TAO Tao, XIE Zili, LIU Bin, CHEN Dunjun, ZHENG Youdou, ZHANG Rong, WANG Ke. Study on Molecular Beam Epitaxy of High Al Content AlGaN Thin Films and Si Doping[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2023, 52(5): 783-790.

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