Leakage current through the poly-crystalline HfO2: Trap densities at grains and grain boundaries
Leakage current through the poly-crystalline HfO2: Trap densities at grains and grain boundaries
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DOI：
10.1063/1.4823854
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发表时间：
2013-10
影响因子：
3.2
通讯作者：
O. Pirrotta;L. Larcher;M. Lanza;A. Padovani;M. Porti;M. Nafría;G. Bersuker
中科院分区：
文献类型：
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作者：
O. Pirrotta;L. Larcher;M. Lanza;A. Padovani;M. Porti;M. Nafría;G. Bersuker
我们调查的晶粒和晶界（GBs）的作用，通过多晶HfO 2的电子输运通过导电原子力显微镜（CAFM）测量和陷阱辅助隧道模拟。CAFM实验表明，通过薄介质膜的漏电流优先流经GB。利用多声子陷阱辅助隧穿模型成功地模拟了两种类型的网站，晶粒和GB上测量的电流I-V特性，该模型解释了通过电子陷阱的非弹性电荷输运。电活性陷阱的能量参数与氧化铟中带正电荷的氧空位的能量参数相匹配，在晶粒处的电活性陷阱的提取密度为103 × 1019 cm−3，而要再现通过GB的漏电流，则需要更高的值（0.9 × 2.1）× 1021 cm−3。
We investigate the role of grains and grain boundaries (GBs) in the electron transport through poly-crystalline HfO2 by means of conductive atomic force microscopy (CAFM) measurements and trap-assisted tunneling simulations. CAFM experiments demonstrate that the leakage current through a thin dielectric film preferentially flows via the GBs. The current I-V characteristics measured on both types of sites, grains, and GBs are successfully simulated by utilizing the multiphonon trap-assisted tunneling model, which accounts for the inelastic charge transport via the electron traps. The extracted density of electrically active traps, whose energy parameters match those of the positively charged oxygen vacancies in hafnia, is ∼3 × 1019 cm−3 at the grains, whereas a much higher value of (0.9÷2.1) × 1021 cm−3 is required to reproduce the leakage current through the GBs.