p型4H-SiC单晶衬底表征及第一性原理计算  

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

作　　者：罗东 贾伟[1] 王英民 戴鑫 贾志刚 董海亮[1] 李天保[4] 王利忠 许并社[1] LUO Dong;JIA Wei;WANG Yingmin;DAI Xin;JIA Zhigang;DONG Hailiang;LI Tianbao;WANG Lizhong;XU Bingshe(Key Laboratory of Interface Science and Engineering in Advanced Materials,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;The 46th Research Institute,China Electronics Technology Group Corporation,Tianjin 300220,China;Shanxi Semicore Crystal Co.,Ltd.,Taiyuan 030024,China;College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[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

出　　处：《人工晶体学报》2022年第7期1169-1176,共8页Journal of Synthetic Crystals

基　　金：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)。

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0.5Ω·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。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 0.5Ω·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.

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 

分 类 号：O469[理学—凝聚态物理]