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人工晶体学报 ›› 2022, Vol. 51 ›› Issue (7): 1169-1176.

• 研究论文 • 上一篇    下一篇

p型4H-SiC单晶衬底表征及第一性原理计算

罗东1, 贾伟1, 王英民2, 戴鑫3, 贾志刚1, 董海亮1, 李天保4, 王利忠3, 许并社1   

  1. 1.太原理工大学,新材料界面科学与工程教育部重点实验室,太原 030024;
    2.中国电子科技集团公司第四十六研究所,天津 300220;
    3.山西烁科晶体有限公司,太原 030024;
    4.太原理工大学材料科学与工程学院,太原 030024
  • 收稿日期:2022-02-25 出版日期:2022-07-15 发布日期:2022-08-11
  • 通讯作者: 贾 伟,博士,高级实验师。E-mail:jiawei@tyut.edu.cn王英民,博士,高级工程师。E-mail:wymzll@126.com
  • 作者简介:罗 东(1996—),男,山西省人,硕士研究生。E-mail:475166658@qq.com
  • 基金资助:
    山西省重点研发项目(201903D111009);山西浙大新材料与化工研究院(2021SX-AT002);国家自然科学基金(61604104,21972103,61904120);山西省自然科学基金(201901D111109)

Characterization and First-Principles Calculations of p-Type 4H-SiC Single Crystal Substrates

LUO Dong1, JIA Wei1, WANG Yingmin2, DAI Xin3, JIA Zhigang1, DONG Hailiang1, LI Tianbao4, WANG Lizhong3, XU Bingshe1   

  1. 1. Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China;
    2. The 46th Research Institute, China Electronics Technology Group Corporation, Tianjin 300220, China;
    3. Shanxi Semicore Crystal Co., Ltd., Taiyuan 030024, China;
    4. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
  • Received:2022-02-25 Online:2022-07-15 Published:2022-08-11

摘要: p型4H-SiC是制备高功率电力电子器件的理想衬底材料,但由于工艺技术的制约,国内尚无能力生产高质量、大尺寸、低电阻的p型4H-SiC单晶衬底。本文使用物理气相传输(PVT)法制备了直径为4英寸(1英寸=2.54 cm)Al掺杂的p型4H-SiC单晶衬底。通过KOH腐蚀表征样品位错密度,使用高分辨X射线衍射(HRXRD)表征其晶体质量,利用拉曼光谱扫描确定其晶型,采用非接触式电阻测试仪测试其电阻率。结果表明,衬底整体位错密度较低,结晶质量良好,晶型稳定且衬底全片电阻率小于0.5 Ω·cm。通过第一性原理平面波超软赝势方法对本征4H-SiC及Al元素掺杂后样品的体系进行能带结构、电子态密度的计算。结果表明Al掺杂后样品禁带宽度减小,费米能级穿过价带,体现出p型半导体的特征。研究结果为大规模生产高质量、低电阻的p型4H-SiC衬底提供思路。

关键词: p型4H-SiC, 物理气相传输, 单晶衬底, 结构表征, Al掺杂, 第一性原理, 半导体

Abstract: The p-type 4H-SiC are ideal materials of substrate for high-power electronic devices. However, p-type 4H-SiC single crystal substrates with high quality, large size and low resistance could not be produced in China due to technological constraints. In this paper, Al doped p-type 4H-SiC single crystal substrates with a diameter of 4-inch were prepared by physical vapor transport (PVT). Dislocation defects were tested by the corrosion of KOH on the substrate. The crystal quality was characterized by high resolution X-ray diffraction (HRXRD), the crystal polytype was determined by Raman spectrum scanning, and the resistivity was measured by non-contact resistivity tester, respectively. It suggest that as-prepared substrates with low overall dislocation density and total resistivity (less than 0.5 Ω·cm) are prepared, meanwhile their crystal quality are good and crystal polytype is stable. Furthermore, the energy band structure and density of states of pristine 4H-SiC and Al doped p-type 4H-SiC were calculated via the first-principles plane wave ultra-soft pseudopotential method. The results show that the gap width decreases and the Fermi level passes through the valence band after the introduction of Al, which is considered as the characteristics of a p-type semiconductor. This elaborate study pave the way for the large-scale production of the p-type 4H-SiC substrate with high quality and low resistance.

Key words: p-type 4H-SiC, physical vapor transport, single crystal substrate, structure characterization, Al doping, first-principle, semiconductor

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