Improved electrical properties of Ge metal-oxide-semiconductor capacitor with HfTa-based gate dielectric by using TaOxNy interlayer
Improved electrical properties of Ge metal-oxide-semiconductor capacitor with HfTa-based gate dielectric by using TaOxNy interlayer
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DOI：
10.1063/1.2954012
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发表时间：
2008-07
影响因子：
4
通讯作者：
Xinhan Zhang;Jinhua Xu;C. X. Li;P. Lai;C. Chan;J. Guan
中科院分区：
文献类型：
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作者：
Xinhan Zhang;Jinhua Xu;C. X. Li;P. Lai;C. Chan;J. Guan
在Ge衬底上制作了具有或不具有TaOxNy中间层的HfTa基氧化物和氮氧化物，以形成金属氧化物半导体（MOS）电容器。测量和比较了它们的电性能和可靠性。结果表明，采用HfTa基氮氧化物和TaOxNy薄中间层的MOS电容器具有低的界面态/氧化物电荷密度、低的栅漏、小的迟滞、小的电容等效厚度（≤ 0.94nm）和高的介电常数（≤ 24）。所有这些都应归因于TaOxNy夹层对O渗透到Ge衬底和Hf，Ge和Ta的互扩散的阻挡作用，从而有效地抑制了不稳定的低k GeOx的形成，并给出了上级TaOxNy闪烁Ge界面。此外，将N结合到夹层和高k电介质中通过形成强N相关键大大提高了器件的可靠性。
HfTa-based oxide and oxynitride with or without TaOxNy interlayer are fabricated on Ge substrate to form metal-oxide-semiconductor (MOS) capacitors. Their electrical properties and reliabilities are measured and compared. The results show that the MOS capacitor with a gate stack of HfTa-based oxynitride and thin TaOxNy interlayer exhibits low interface-state/oxide-charge densities, low gate leakage, small hysteresis, small capacitance equivalent thickness (∼0.94nm), and high dielectric constant (∼24). All these should be attributed to the blocking role of the TaOxNy interlayer against penetration of O into the Ge substrate and interdiffusions of Hf, Ge, and Ta, thus effectively suppressing the formation of unstable low-k GeOx and giving a superior TaOxNy∕Ge interface. Moreover, incorporation of N into both the interlayer and high-k dielectric greatly improves device reliability through the formation of strong N-related bonds.