Ferroelectric transistor model based on self-consistent solution of 2D Poisson's, non-equilibrium Green's function and multi-domain Landau Khalatnikov equations
Ferroelectric transistor model based on self-consistent solution of 2D Poisson's, non-equilibrium Green's function and multi-domain Landau Khalatnikov equations
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DOI：
10.1109/iedm.2017.8268385
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发表时间：
2017-12
期刊：
影响因子：
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通讯作者：
A. Saha;P. Sharma;I. Dabo;S. Datta;S. Gupta
中科院分区：
文献类型：
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作者：
A. Saha;P. Sharma;I. Dabo;S. Datta;S. Gupta
我们提出了一种基于物理的铁电/负电容晶体管 (FEFET/NCFET) 模型，在栅极堆叠中的铁电和电介质之间没有层间金属。该模型自洽求解二维泊松方程、基于非平衡格林函数 (NEGF) 的电荷和输运方程以及具有域相互作用项的多域 Landau Khalatnikov (LK) 方程。所提出的模拟框架捕获了由于沿沟道的不均匀电场 (E) 导致铁电 (FE) 极化 (P) 沿栅极长度的变化。为了校准 LK 方程，我们制造并表征了 10 nm HZO 薄膜。基于校准模型，我们分析了FE中P分布的栅极/漏极电压依赖性及其对沟道电位和电流-电压特性的影响。我们的结果强调了更大的域相互作用对于提高 FEFET 的优势的重要性，在室温下实现亚阈值摆幅 (SS) 小至 ∼50mV/十倍频程。随着域相互作用的增加，没有层间金属（SS、负漏极感应势垒降低 (DIBL)、负输出电导）的 FEFET 的特性接近有层间金属的 FEFET 的特性。
We present a physics-based model for ferroelectric/negative capacitance transistors (FEFETs/ NCFETs) without an inter-layer metal between ferroelectric and dielectric in the gate stack. The model self-consistently solves 2D Poisson's equation, non-equilibrium Green's function (NEGF) based charge and transport equations, and multi-domain Landau Khalatnikov (LK) equations with the domain interaction term. The proposed simulation framework captures the variation of ferroelectric (FE) polarization (P) along the gate length due to non-uniform electric field (E) along the channel. To calibrate the LK equations, we fabricate and characterize 10nm HZO films. Based on the calibrated model, we analyze the gate/drain voltage dependence of P distribution in the FE and its effect on the channel potential and current-voltage characteristics. Our results highlight the importance of larger domain interaction to boost the benefits of FEFETs with subthreshold swing (SS) as small as ∼50mV/decade achieved at room temperature. As domain interaction increases, the characteristics of FEFETs without inter-layer metal (SS, negative drain induced barrier lowering (DIBL), negative output conductance) approach those of FEFETs with inter-layer metal.