中国物理B ›› 2012, Vol. 21 ›› Issue (8): 87701-087701.doi: 10.1088/1674-1056/21/8/087701

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Investigation of 4H–SiC metal–insulation–semiconductor structure with Al2O3/SiO2 stacked dielectric

汤晓燕, 宋庆文, 张玉明, 张义门, 贾仁需, 吕红亮, 王悦湖   

  1. School Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • 收稿日期:2012-02-10 修回日期:2012-02-22 出版日期:2012-07-01 发布日期:2012-07-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61006060 and 61176070).

Investigation of 4H–SiC metal–insulation–semiconductor structure with Al2O3/SiO2 stacked dielectric

Tang Xiao-Yan (汤晓燕), Song Qing-Wen (宋庆文), Zhang Yu-Ming (张玉明), Zhang Yi-Men (张义门), Jia Ren-Xu (贾仁需), Lü Hong-Liang(吕红亮), Wang Yue-Hu (王悦湖 )   

  1. School Microelectronics, Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071, China
  • Received:2012-02-10 Revised:2012-02-22 Online:2012-07-01 Published:2012-07-01
  • Contact: Tang Xiao-Yan E-mail:xytang@mail.xidian.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61006060 and 61176070).

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摘要： Atomic layer deposited (ALD) Al2O3/dry-oxidized ultrathin SiO2 films as high-k gate dielectric grown on the 8° off-axis 4H-SiC (0001) epitaxial wafers are investigated in this paper. The metal-insulation-semiconductor (MIS) capacitors, respectively with different gate dielectric stacks (Al2O3/SiO2, Al2O3, and SiO2) are fabricated and compared with each other. The I-V measurements show that the Al2O3/SiO2 stack has a high breakdown field ( ≥ 12 MV/cm) comparable to SiO2, and a relatively low gate leakage current of 1× 10-7 A/cm2 at electric field of 4 MV/cm comparable to Al2O3. The 1-MHz high frequency C-V measurements exhibit that the Al2O3/SiO2 stack has a smaller positive flat-band voltage shift and hysteresis voltage, indicating less effective charge and slow-trap density near the interface.

关键词: 4H-SiC, Al2O3, high-k dielectric

Abstract: Atomic layer deposited (ALD) Al2O3/dry-oxidized ultrathin SiO2 films as high-k gate dielectric grown on the 8° off-axis 4H-SiC (0001) epitaxial wafers are investigated in this paper. The metal-insulation-semiconductor (MIS) capacitors, respectively with different gate dielectric stacks (Al2O3/SiO2, Al2O3, and SiO2) are fabricated and compared with each other. The I-V measurements show that the Al2O3/SiO2 stack has a high breakdown field ( ≥ 12 MV/cm) comparable to SiO2, and a relatively low gate leakage current of 1× 10-7 A/cm2 at electric field of 4 MV/cm comparable to Al2O3. The 1-MHz high frequency C-V measurements exhibit that the Al2O3/SiO2 stack has a smaller positive flat-band voltage shift and hysteresis voltage, indicating less effective charge and slow-trap density near the interface.

Key words: 4H-SiC, Al2O3, high-k dielectric

中图分类号:  (Dielectric breakdown and space-charge effects)

  • 77.22.Jp
73.20.-r (Electron states at surfaces and interfaces) 77.84.Lf (Composite materials)