中国物理B ›› 2025, Vol. 34 ›› Issue (6): 67201-067201.doi: 10.1088/1674-1056/adc407

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Prolonging carrier lifetime in P-type 4H-SiC epilayer by thermal oxidation and hydrogen annealing

Ruijun Zhang(张锐军)1, Mingkun Zhang(张明昆)3, Guoliang Zhang(张国良)1, Yujian Chen(陈雨箭)1, Jia Liu(刘佳)1, Ziqian Tian(田自谦)1, Ye Yu(余烨)1,†, Peng Zhao(赵鹏)1, Jiafa Cai(蔡加法)1, Xiaping Chen(陈厦平)1, Dingqu Lin(林鼎渠)1, Shaoxiong Wu(吴少雄)1, Yuning Zhang(张宇宁)1, Xingliang Xu(徐星亮)4, Rongdun Hong(洪荣墩)1,2,‡, and Feng Zhang(张峰)1,2,§   

  1. 1 Department of Physics, Xiamen University, Xiamen 361005, China;
    2 Jiujiang Research Institute of Xiamen University, Jiujiang 332000, China;
    3 The Higher Educational Key Laboratory of Flexible Manufacturing Equipment Integration of Fujian Province, Xiamen Institute of Technology, Xiamen 361005, China;
    4 Microsystem and Terahertz Research Center, Chengdu 610000, China
  • 收稿日期:2025-01-31 修回日期:2025-03-09 接受日期:2025-03-24 出版日期:2025-05-16 发布日期:2025-06-06
  • 通讯作者: Ye Yu, Rongdun Hong, Feng Zhang E-mail:yu.ye@sicty.com;rdhong@xmu.edu.cn;fzhang@xmu.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2023YFB3609500 and 2023YFB3609502), the National Natural Science Foundation of China (Grant No. 62274137), the Natural Science Foundation of Jiangxi Province, China (Grant No. 20232BAB202043), and the Science and Technology Project of Fujian Province of China (Grant No. 2020I0001).

Prolonging carrier lifetime in P-type 4H-SiC epilayer by thermal oxidation and hydrogen annealing

Ruijun Zhang(张锐军)1, Mingkun Zhang(张明昆)3, Guoliang Zhang(张国良)1, Yujian Chen(陈雨箭)1, Jia Liu(刘佳)1, Ziqian Tian(田自谦)1, Ye Yu(余烨)1,†, Peng Zhao(赵鹏)1, Jiafa Cai(蔡加法)1, Xiaping Chen(陈厦平)1, Dingqu Lin(林鼎渠)1, Shaoxiong Wu(吴少雄)1, Yuning Zhang(张宇宁)1, Xingliang Xu(徐星亮)4, Rongdun Hong(洪荣墩)1,2,‡, and Feng Zhang(张峰)1,2,§   

  1. 1 Department of Physics, Xiamen University, Xiamen 361005, China;
    2 Jiujiang Research Institute of Xiamen University, Jiujiang 332000, China;
    3 The Higher Educational Key Laboratory of Flexible Manufacturing Equipment Integration of Fujian Province, Xiamen Institute of Technology, Xiamen 361005, China;
    4 Microsystem and Terahertz Research Center, Chengdu 610000, China
  • Received:2025-01-31 Revised:2025-03-09 Accepted:2025-03-24 Online:2025-05-16 Published:2025-06-06
  • Contact: Ye Yu, Rongdun Hong, Feng Zhang E-mail:yu.ye@sicty.com;rdhong@xmu.edu.cn;fzhang@xmu.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant Nos. 2023YFB3609500 and 2023YFB3609502), the National Natural Science Foundation of China (Grant No. 62274137), the Natural Science Foundation of Jiangxi Province, China (Grant No. 20232BAB202043), and the Science and Technology Project of Fujian Province of China (Grant No. 2020I0001).

摘要: A minority carrier lifetime of 25.46 μs in a P-type 4H-SiC epilayer has been attained through sequential thermal oxidation and hydrogen annealing. Thermal oxidation can enhance the minority carrier lifetime in the 4H-SiC epilayer by reducing carbon vacancies. However, this process also generates carbon clusters with limited diffusivity and contributes to the enlargement of surface pits on the 4H-SiC. High-temperature hydrogen annealing effectively reduces stacking fault and dislocation density. Moreover, electron spin resonance analysis indicates a significant reduction in carbon vacancy defects after hydrogen annealing. The mechanisms of the elimination of carbon vacancies by hydrogen annealing include the decomposition of carbon clusters formed during thermal oxidation and the low-pressure selective etching by hydrogen, which increases the carbon content on the 4H-SiC surface and facilitates carbon diffusion. Consequently, the combination of thermal oxidation and hydrogen annealing eliminates carbon vacancies more effectively, substantially enhancing the minority carrier lifetime in P-type 4H-SiC. This improvement is advantageous for the application of high-voltage SiC bipolar devices.

关键词: 4H-SiC, carrier lifetime, thermal oxidation, hydrogen annealing

Abstract: A minority carrier lifetime of 25.46 μs in a P-type 4H-SiC epilayer has been attained through sequential thermal oxidation and hydrogen annealing. Thermal oxidation can enhance the minority carrier lifetime in the 4H-SiC epilayer by reducing carbon vacancies. However, this process also generates carbon clusters with limited diffusivity and contributes to the enlargement of surface pits on the 4H-SiC. High-temperature hydrogen annealing effectively reduces stacking fault and dislocation density. Moreover, electron spin resonance analysis indicates a significant reduction in carbon vacancy defects after hydrogen annealing. The mechanisms of the elimination of carbon vacancies by hydrogen annealing include the decomposition of carbon clusters formed during thermal oxidation and the low-pressure selective etching by hydrogen, which increases the carbon content on the 4H-SiC surface and facilitates carbon diffusion. Consequently, the combination of thermal oxidation and hydrogen annealing eliminates carbon vacancies more effectively, substantially enhancing the minority carrier lifetime in P-type 4H-SiC. This improvement is advantageous for the application of high-voltage SiC bipolar devices.

Key words: 4H-SiC, carrier lifetime, thermal oxidation, hydrogen annealing

中图分类号:  (Charge carriers: generation, recombination, lifetime, and trapping)

  • 72.20.Jv
72.80.Jc (Other crystalline inorganic semiconductors)