中国物理B ›› 2015, Vol. 24 ›› Issue (3): 38103-038103.doi: 10.1088/1674-1056/24/3/038103

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Energy-band alignment of atomic layer deposited (HfO2)x(Al2O3)1-x gate dielectrics on 4H-SiC

贾仁需a, 董林鹏a, 钮应喜b, 李诚瞻c, 宋庆文a, 汤晓燕a, 杨霏b, 张玉明a   

  1. a School of Microelectronics, Xidian University, Xi'an 710071, China;
    b State Grid Smart Grid Research Institute, Beijing 100192, China;
    c Zhuzhou CSR Times Electric Co., Ltd., Zhuzhou 412001, China
  • 收稿日期:2014-10-11 修回日期:2014-12-06 出版日期:2015-03-05 发布日期:2015-03-05
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 51272202 and 61234006) and the Science Project of State Grid, China (Grant No. SGRI-WD-71-14-004).

Energy-band alignment of atomic layer deposited (HfO2)x(Al2O3)1-x gate dielectrics on 4H-SiC

Jia Ren-Xu (贾仁需)a, Dong Lin-Peng (董林鹏)a, Niu Ying-Xi (钮应喜)b, Li Cheng-Zhan (李诚瞻)c, Song Qing-Wen (宋庆文)a, Tang Xiao-Yan (汤晓燕)a, Yang Fei (杨霏)b, Zhang Yu-Ming (张玉明)a   

  1. a School of Microelectronics, Xidian University, Xi'an 710071, China;
    b State Grid Smart Grid Research Institute, Beijing 100192, China;
    c Zhuzhou CSR Times Electric Co., Ltd., Zhuzhou 412001, China
  • Received:2014-10-11 Revised:2014-12-06 Online:2015-03-05 Published:2015-03-05
  • Contact: Jia Ren-Xu E-mail:rxjia@mail.xidian.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 51272202 and 61234006) and the Science Project of State Grid, China (Grant No. SGRI-WD-71-14-004).

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摘要：

We study a series of (HfO2)x(Al2O3)1-x/4H-SiC MOS capacitors. It is shown that the conduction band offset of HfO2 is 0.5 eV and the conduction band offset of HfAlO is 1.11-1.72 eV. The conduction band offsets of (HfO2)x(Al2O3)1-x are increased with the increase of the Al composition, and the (HfO2)x(Al2O3)1-x offer acceptable barrier heights (> 1 eV) for both electrons and holes. With a higher conduction band offset, (HfO2)x(Al2O3)1-x/4H-SiC MOS capacitors result in a ～ 3 orders of magnitude lower gate leakage current at an effective electric field of 15 MV/cm and roughly the same effective breakdown field of ～ 25 MV/cm compared to HfO2. Considering the tradeoff among the band gap, the band offset, and the dielectric constant, we conclude that the optimum Al2O3 concentration is about 30% for an alternative gate dielectric in 4H-SiC power MOS-based transistors.

关键词: energy-band alignment, high k gate dielectrics, 4H-SiC MOS capacitor

Abstract:

We study a series of (HfO2)x(Al2O3)1-x/4H-SiC MOS capacitors. It is shown that the conduction band offset of HfO2 is 0.5 eV and the conduction band offset of HfAlO is 1.11-1.72 eV. The conduction band offsets of (HfO2)x(Al2O3)1-x are increased with the increase of the Al composition, and the (HfO2)x(Al2O3)1-x offer acceptable barrier heights (> 1 eV) for both electrons and holes. With a higher conduction band offset, (HfO2)x(Al2O3)1-x/4H-SiC MOS capacitors result in a ～ 3 orders of magnitude lower gate leakage current at an effective electric field of 15 MV/cm and roughly the same effective breakdown field of ～ 25 MV/cm compared to HfO2. Considering the tradeoff among the band gap, the band offset, and the dielectric constant, we conclude that the optimum Al2O3 concentration is about 30% for an alternative gate dielectric in 4H-SiC power MOS-based transistors.

Key words: energy-band alignment, high k gate dielectrics, 4H-SiC MOS capacitor

中图分类号:  (Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization)

  • 81.40.Ef
73.20.-r (Electron states at surfaces and interfaces) 73.40.Qv (Metal-insulator-semiconductor structures (including semiconductor-to-insulator))