Effects of Low Temperature Electronic Cyclotron Resonance Hydrogen Plasma Treatment and Annealing on the Electrical Properties of Ti and Ni Contacts to 4H-SiC
Effects of Low Temperature Electronic Cyclotron Resonance Hydrogen Plasma Treatment and Annealing on the Electrical Properties of Ti and Ni Contacts to 4H-SiC
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DOI：
10.1143/jjap.51.081302
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发表时间：
2012-07
影响因子：
1.5
通讯作者：
Lingqi Huang;Qiaozhi Zhu;M. Gao;F. Qin;Dejun Wang
中科院分区：
文献类型：
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作者：
Lingqi Huang;Qiaozhi Zhu;M. Gao;F. Qin;Dejun Wang
研究了低温电子回旋共振微波氢等离子体预处理和后退火对Ti和Ni与4 H-SiC接触电性能的影响。HPT显著改善了Ti/4 H-SiC接触的欧姆特性。与此相反，它显着提高整流行为的Ni/4 H-SiC接触。Ti欧姆接触和Ni整流接触的性能随着退火温度的升高而改善，直到400 °C。然而，在400 °C以上它们就会变质。X射线光电子能谱测量证实，表面费米能级（EFs）移动到导带边缘的HPT。经400 °C退火后，样品的表面态密度达到4.43×1011 cm-2 eV-1，接近体费米能级。然而，在高于400 °C的退火之后，随着Ds的增加，EFs移回到更接近中间带隙。实验结果符合Cowley和Sze的势垒高度理论。
The effects of low temperature electronic cyclotron resonance microwave hydrogen plasma pretreatment and post-annealing on the electrical properties of Ti and Ni contacts to 4H-SiC were investigated. The HPT improves the Ohmic behavior of Ti/4H-SiC contact significantly. In contrast, it remarkably enhances the rectifying behavior of Ni/4H-SiC contact. The properties of Ti Ohmic contact and Ni rectifying contact improve with increasing annealing temperature up to 400 °C. However, they are deteriorated above 400 °C. X-ray photoelectron spectroscopy measurements confirm that the surface Fermi level (EFs) moves toward the conduction band edge by the HPT. It almost attains the bulk Femi level position after annealing at 400 °C with the surface states density (Ds) as low as 4.43×1011 cm-2 eV-1. However, after annealing above 400 °C, EFs moves back closer to midgap with an increase of Ds. The experimental results are found to obey the barrier height theory of Cowley and Sze.