摘要
Thermal oxidation and hydrogen annealing were applied on a 100μm thick Al-doped p-type 4H-Si C 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 to3 hours,the minority carrier lifetime increased from 1.1μs(as-grown)to 3.14μs 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 1.94μs 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.
作者
张锐军
洪荣墩
韩景瑞
丁雄杰
李锡光
蔡加法
陈厦平
傅德颐
林鼎渠
张明昆
吴少雄
张宇宁
吴正云
张峰
Ruijun Zhang;Rongdun Hong;Jingrui Han;Hungkit Ting;Xiguang Li;Jiafa Cai;Xiaping Chen;Deyi Fu;Dingqu Lin;Mingkun Zhang;Shaoxiong Wu;Yuning Zhang;Zhengyun Wu;Feng Zhang(Department of physics,Xiamen university,Xiamen 361005,China;Guangdong Tianyu Semiconductor Co.,Ltd,Dongguan 523808,China)
基金
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)
the Science and Technology Key Projects of Xiamen(Grant No.3502ZCQ20191001)
the National Natural Science Foundation of China(Grant No.51871189)。