Limitations of the uniform effective field approximation due to doping of ferroelectric thin‐film capacitors
Limitations of the uniform effective field approximation due to doping of ferroelectric thin‐film capacitors
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DOI：
10.1063/1.359823
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发表时间：
1995-10
影响因子：
3.2
通讯作者：
Francis K. Chai;J. Brews;peixiong zhao;D. Birnie
中科院分区：
文献类型：
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作者：
Francis K. Chai;J. Brews;peixiong zhao;D. Birnie
铁电电容器中的电场分布通常被视为电路级建模的均匀有效场。通过求解泊松方程并将铁电电容器视为背对背肖特基势垒系统，计算铁电薄膜内部的非均匀电场分布，假设薄膜电容器完全耗尽且具有恒定的掺杂浓度。研究发现，局部场与均匀有效场的偏离随着薄膜掺杂浓度的增加而增加。在该模型中，当掺杂水平足够大以致于即使在零偏置下表面场也超过矫顽场时，用于提取微观铁电参数的均匀场方法是不准确的。基于这个标准，使用均匀场近似进行参数提取的临界掺杂浓度被发现约为5×1017 cm−3。也就是说，根据假设的模型，对于高 dop...
The electric‐field distribution in a ferroelectric capacitor often is treated as a uniform effective field for circuit‐level modeling. By solving Poisson’s equation and treating the ferroelectric capacitor as a back‐to‐back Schottky‐barrier system, the nonuniform electric‐field distribution is calculated inside a ferroelectric thin film, assuming that the thin‐film capacitor is completely depleted and has a constant doping concentration. It is found that the departure of the local field from the uniform effective field increases with an increase in the doping concentration of the film. Within this model, the uniform field approach to extraction of microscopic ferroelectric parameters is inaccurate for doping levels great enough that the surface field exceeds the coercive field even at zero bias. Based on this criterion, the critical doping concentration for parameter extraction using the uniform field approximation is found to be about 5×1017 cm−3. That is, according to the assumed model, for the high dop...