Improved electrical properties of Ge metal-oxide-semiconductor capacitors with high-k HfO2 gate dielectric by using La2O3 interlayer sputtered with/without N2 ambient
Improved electrical properties of Ge metal-oxide-semiconductor capacitors with high-k HfO2 gate dielectric by using La2O3 interlayer sputtered with/without N2 ambient
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DOI：
10.1063/1.3462301
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发表时间：
2010-07
影响因子：
4
通讯作者：
H. Xu;Jiqu Xu;C. X. Li;P. Lai
中科院分区：
文献类型：
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作者：
H. Xu;Jiqu Xu;C. X. Li;P. Lai
研究了HfO2/LaON或HfO2/La2O3叠层栅极介质（LaON或La2O3为中间层）的n-Ge金属氧化物半导体（MOS）电容器的电学性能。结果表明，采用LaON中间层的MOS器件具有较低的界面态密度、较小的栅漏电流、较小的电容等效厚度、较大的k值和可忽略的C-V频散等电学性能。其机制在于LaON中间层可以有效阻断Ge、O和Hf的相互扩散，从而抑制不稳定GeOx中间层的生长，提高介电/Ge界面质量。
The electrical properties of n-Ge metal-oxide-semiconductor (MOS) capacitors with HfO2/LaON or HfO2/La2O3 stacked gate dielectric (LaON or La2O3 as interlayer) are investigated. It is found that better electrical performances, including lower interface-state density, smaller gate leakage current, smaller capacitance equivalent thickness, larger k value, and negligible C-V frequency dispersion, can be achieved for the MOS device with LaON interlayer. The involved mechanism lies in that the LaON interlayer can effectively block the interdiffusions of Ge, O, and Hf, thus suppressing the growth of unstable GeOx interlayer and improving the dielectric/Ge interface quality.