Theoretical study on the improvement of the doping efficiency of Al in 4H-SiC by co-doping group-ⅣB elements

• 作者: Yuanchao Huang Rong Wang Yixiao Qian Yiqiang Zhang Deren Yang Xiaodong Pi
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2022,（4）
• 所属期刊栏目: CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROP-ERTIES
• 页码范围: 577-582
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/ac20ca

摘要

The p-type doping efficiency of 4H silicon carbide(4H-SiC)is rather low due to the large ionization energies of p-type dopants.Such an issue impedes the exploration of the full advantage of 4H-SiC for semiconductor devices.In this study,we show that co-doping group-ⅣB elements effectively decreases the ionization energy of the most widely used p-type dopant,i.e.,aluminum(Al),through the defect-level repulsion between the energy levels of group-ⅣB elements and that of Al in 4H-SiC.Among group-ⅣB elements Ti has the most prominent effectiveness.Ti decreases the ionization energy of Al by nearly 50％,leading to a value as low as～0.13 eV.As a result,the ionization rate of Al with Ti co-doping is up to～5 times larger than that without co-doping at room temperature when the doping concentration is up to 1018 cm-3.This work may encourage the experimental co-doping of group-ⅣB elements such as Ti and Al to significantly improve the p-type doping efficiency of 4H-SiC.