Energy-band alignment of atomic layer deposited (HfO2)(x)(Al2O3)(1-x) gate dielectrics on 4H-SiC
Energy-band alignment of atomic layer deposited (HfO2)(x)(Al2O3)(1-x) gate dielectrics on 4H-SiC
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4H-SiC 上沉积 (HfO2)(x)(Al2O3)(1-x) 栅极电介质原子层的能带排列
DOI：
10.1088/1674-1056/24/3/038103
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发表时间：
2015
影响因子：
1.7
通讯作者：
Zhang Yu-Ming
中科院分区：
文献类型：
--
作者：
Jia Ren-Xu;Dong Lin-Peng;Niu Ying-Xi;Li Cheng-Zhan;Song Qing-Wen;Tang Xiao-Yan;Yang Fei;Zhang Yu-Ming
我们研究了一系列（HfO 2） x (Al 2o3) 1−x/4H-SiC MOS电容器。结果表明，HfO 2的导带偏置为0.5 eV， HfAlO的导带偏置为1.11 ~ 1.72 eV。（HfO 2） x (Al 2o3) 1−x的导带偏移量随着Al成分的增加而增加，并且（HfO 2） x (Al 2o3) 1−x对电子和空穴都提供了可接受的势垒高度（bbb1ev）。在较高的导带偏置下，（HfO 2） x (Al 2o3) 1−x/4H-SiC MOS电容器在15 MV/cm的有效电场下的栅漏电流降低了约3个数量级，与HfO 2相比，有效击穿场大致相同，约25 MV/cm。考虑到带隙、带偏和介电常数之间的权衡，我们得出结论，在4H-SiC功率mos基晶体管中，最佳的Al 2o3浓度约为30%。
We study a series of (HfO 2) x (Al 2 O 3) 1− x/4H-SiC MOS capacitors. It is shown that the conduction band offset of HfO 2 is 0.5 eV and the conduction band offset of HfAlO is 1.11–1.72 eV. The conduction band offsets of (HfO 2) x (Al 2 O 3) 1− x are increased with the increase of the Al composition, and the (HfO 2) x (Al 2 O 3) 1− x offer acceptable barrier heights (> 1 eV) for both electrons and holes. With a higher conduction band offset,(HfO 2) x (Al 2 O 3) 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 HfO 2. Considering the tradeoff among the band gap, the band offset, and the dielectric constant, we conclude that the optimum Al 2 O 3 concentration is about 30% for an alternative gate dielectric in 4H-SiC power MOS-based transistors.