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