Insights into ultraviolet-induced electrical degradation of thermally grown SiO2/4H-SiC(0001) interface
Insights into ultraviolet-induced electrical degradation of thermally grown SiO2/4H-SiC(0001) interface
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DOI：
10.1063/1.4860987
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发表时间：
2014-01-06
影响因子：
4
通讯作者：
Watanabe, Heiji
中科院分区：
文献类型：
--
作者：
Ikeguchi, Daisuke;Hosoi, Takuji;Watanabe, Heiji
通过测量金属氧化物半导体（MOS）电容器的电学性能，研究了紫外光辐照对热生长SiO2/4 H-SiC结构的有害影响。与Si基MOS器件不同，SiC-MOS电容器的电容-电压（C-V）曲线中的正平带电压（V-FB）漂移和滞后等显著的电退化是由低压汞灯紫外辐照引起的。界面固定电荷密度随着紫外光照射（22.6 mW/cm（2），16 h）而增加到1.7 x 10（12）cm（-2），比生长态SiO2/SiC界面的固定电荷密度大一个数量级。基于单波长固态UV激光器的详细研究表明，在约5eV处存在阈值光子能量，并且UV诱导的降解对温度具有适度的依赖性。这些实验结果意味着，预先存在的非活性缺陷积累在热生长的SiO2/SiC界面转化为活性载流子陷阱与高能量的紫外线照射通过透明的SiO2层。(C)2014 AIP Publishing LLC.
The harmful impact of ultraviolet (UV) light irradiation on thermally grown SiO2/4H-SiC structures was investigated by means of electrical measurements of metal-oxide-semiconductor (MOS) capacitors. Unlike Si-based MOS devices, significant electrical degradation, such as positive flatband voltage (V-FB) shift and hysteresis in the capacitance-voltage (C-V) curves of SiC-MOS capacitors was induced by UV irradiation with a low-pressure mercury lamp. The interfacial fixed charge density increased with UV-irradiation (22.6 mW/cm(2) for 16 h) to 1.7 x 10(12) cm(-2), which was an order of magnitude larger than that of the as-grown SiO2/SiC interface. A detailed study based on single wavelength solid-state UV lasers revealed that there was a threshold photon energy at around 5 eV and a moderate dependence of UV-induced degradation on temperature. These experimental findings imply that pre-existing inactive defects accumulated at the thermally grown SiO2/SiC interface were transformed to active carrier traps with high-energy UV irradiation through transparent SiO2 layers. (C) 2014 AIP Publishing LLC.