中国物理B ›› 2023, Vol. 32 ›› Issue (6): 67205-067205.doi: 10.1088/1674-1056/ac89db

所属专题: SPECIAL TOPIC — Celebrating the 100th Anniversary of Physics Discipline of Xiamen University

• • 上一篇    下一篇

Impacts of hydrogen annealing on the carrier lifetimes in p-type 4H-SiC after thermal oxidation

Ruijun Zhang(张锐军)1, Rongdun Hong(洪荣墩)1,†, Jingrui Han(韩景瑞)2, Hungkit Ting(丁雄杰)2, Xiguang Li(李锡光)2, Jiafa Cai(蔡加法)1, Xiaping Chen(陈厦平)1, Deyi Fu(傅德颐)1, Dingqu Lin(林鼎渠)1, Mingkun Zhang(张明昆)1, Shaoxiong Wu(吴少雄)1, Yuning Zhang(张宇宁)1, Zhengyun Wu(吴正云)1, and Feng Zhang(张峰)1,‡   

  1. 1 Department of physics, Xiamen university, Xiamen 361005, China;
    2 Guangdong Tianyu Semiconductor Co., Ltd, Dongguan 523808, China
  • 收稿日期:2022-07-01 修回日期:2022-08-08 接受日期:2022-08-16 出版日期:2023-05-17 发布日期:2023-05-17
  • 通讯作者: Rongdun Hong, Feng Zhang E-mail:rdhong@xmu.edu.cn;fzhang@xmu.edu.cn
  • 基金资助:
    Project supported by Key Area Research and Development Project of Guangdong Province, China (Grant No. 2020B010170002), the Science Challenge Project (Grant No. TZ2018003-1-101), the Natural Science Foundation of Fujian Province of China for Distinguished Young Scholars (Grant No. 2020J06002), the Science and Technology Project of Fujian Province of China (Grant No. 2020I0001), the Fundamental Research Funds for the Central Universities (Grant Nos. 20720190049 and 20720190053), and the Science and Technology Key Projects of Xiamen (Grant No. 3502ZCQ20191001), and the National Natural Science Foundation of China (Grant No. 51871189).

Impacts of hydrogen annealing on the carrier lifetimes in p-type 4H-SiC after thermal oxidation

Ruijun Zhang(张锐军)1, Rongdun Hong(洪荣墩)1,†, Jingrui Han(韩景瑞)2, Hungkit Ting(丁雄杰)2, Xiguang Li(李锡光)2, Jiafa Cai(蔡加法)1, Xiaping Chen(陈厦平)1, Deyi Fu(傅德颐)1, Dingqu Lin(林鼎渠)1, Mingkun Zhang(张明昆)1, Shaoxiong Wu(吴少雄)1, Yuning Zhang(张宇宁)1, Zhengyun Wu(吴正云)1, and Feng Zhang(张峰)1,‡   

  1. 1 Department of physics, Xiamen university, Xiamen 361005, China;
    2 Guangdong Tianyu Semiconductor Co., Ltd, Dongguan 523808, China
  • Received:2022-07-01 Revised:2022-08-08 Accepted:2022-08-16 Online:2023-05-17 Published:2023-05-17
  • Contact: Rongdun Hong, Feng Zhang E-mail:rdhong@xmu.edu.cn;fzhang@xmu.edu.cn
  • Supported by:
    Project supported by Key Area Research and Development Project of Guangdong Province, China (Grant No. 2020B010170002), the Science Challenge Project (Grant No. TZ2018003-1-101), the Natural Science Foundation of Fujian Province of China for Distinguished Young Scholars (Grant No. 2020J06002), the Science and Technology Project of Fujian Province of China (Grant No. 2020I0001), the Fundamental Research Funds for the Central Universities (Grant Nos. 20720190049 and 20720190053), and the Science and Technology Key Projects of Xiamen (Grant No. 3502ZCQ20191001), and the National Natural Science Foundation of China (Grant No. 51871189).

摘要: Thermal oxidation and hydrogen annealing were applied on a 100 μm thick Al-doped p-type 4H-SiC epitaxial wafer to modulate the minority carrier lifetime, which was investigated by microwave photoconductive decay (μ-PCD). The minority carrier lifetime decreased after each thermal oxidation. On the contrary, with the hydrogen annealing time increasing to 3 hours, the minority carrier lifetime increased from 1.1 μs (as-grown) to 3.14 μs and then saturated after the annealing time reached 4 hours. The increase of surface roughness from 0.236 nm to 0.316 nm may also be one of the reasons for limiting the further improvement of the minority carrier lifetimes. Moreover, the whole wafer mappings of minority carrier lifetimes before and after hydrogen annealing were measured and discussed. The average minority carrier lifetime was up to 1.94 μs and non-uniformity of carrier lifetime reached 38% after 4-hour hydrogen annealing. The increasing minority carrier lifetimes could be attributed to the double mechanisms of excess carbon atoms diffusion caused by selective etching of Si atoms and passivation of deep-level defects by hydrogen atoms.

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

Abstract: Thermal oxidation and hydrogen annealing were applied on a 100 μm thick Al-doped p-type 4H-SiC epitaxial wafer to modulate the minority carrier lifetime, which was investigated by microwave photoconductive decay (μ-PCD). The minority carrier lifetime decreased after each thermal oxidation. On the contrary, with the hydrogen annealing time increasing to 3 hours, the minority carrier lifetime increased from 1.1 μs (as-grown) to 3.14 μs and then saturated after the annealing time reached 4 hours. The increase of surface roughness from 0.236 nm to 0.316 nm may also be one of the reasons for limiting the further improvement of the minority carrier lifetimes. Moreover, the whole wafer mappings of minority carrier lifetimes before and after hydrogen annealing were measured and discussed. The average minority carrier lifetime was up to 1.94 μs and non-uniformity of carrier lifetime reached 38% after 4-hour hydrogen annealing. The increasing minority carrier lifetimes could be attributed to the double mechanisms of excess carbon atoms diffusion caused by selective etching of Si atoms and passivation of deep-level defects by hydrogen atoms.

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

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

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