Characterizing THz Scattering Loss in Nano-Scale SOI Waveguides Exhibiting Stochastic Surface Roughness with Exponential Autocorrelation
Characterizing THz Scattering Loss in Nano-Scale SOI Waveguides Exhibiting Stochastic Surface Roughness with Exponential Autocorrelation
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DOI：
10.3390/electronics11030307
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发表时间：
2022-01
期刊：
影响因子：
2.9
通讯作者：
Brian Guiana;A. Zadehgol
中科院分区：
文献类型：
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作者：
Brian Guiana;A. Zadehgol
电磁（EM）散射可能是高对比度绝缘体上硅（SOI）纳米级互连的信号和功率完整性退化的重要来源，所述互连诸如在100 μ s的THz下操作的光电或光学互连，其中电介质平板波导的二维（2D）分析模型通常用于近似散射损耗。在这项工作中，提出了一个配方，散射（传播）损耗的散射参数（S-参数）的光滑波导，结果与结果在二维空间中的时域有限差分法（FDTD）。基于指数自相关函数（ACF）下随机表面粗糙度波导的物理参数，提出了一个归一化因子，并通过与二维FDTD方法数值实验的比较，对数百个粗糙波导进行了仿真，验证了归一化因子的有效性;此外，结果进行了比较，其他2D分析和以前的3D实验结果。FDTD环境进行了描述和验证，通过比较结果的光滑波导对波阻抗，传播常数和S参数的解析解。结果表明，FDTD模型与光滑波导的解析解是一致的，是粗糙波导随机散射损耗的合理近似。
Electromagnetic (EM) scattering may be a significant source of degradation in signal and power integrity of high-contrast silicon-on-insulator (SOI) nano-scale interconnects, such as opto-electronic or optical interconnects operating at 100 s of THz where two-dimensional (2D) analytical models of dielectric slab waveguides are often used to approximate scattering loss. In this work, a formulation is presented to relate the scattering (propagation) loss to the scattering parameters (S-parameters) for the smooth waveguide; the results are correlated with results from the finite-difference time-domain (FDTD) method in 2D space. We propose a normalization factor to the previous 2D analytical formulation for the stochastic scattering loss based on physical parameters of waveguides exhibiting random surface roughness under the exponential autocorrelation function (ACF), and validate the results by comparing against numerical experiments via the 2D FDTD method, through simulation of hundreds of rough waveguides; additionally, results are compared to other 2D analytical and previous 3D experimental results. The FDTD environment is described and validated by comparing results of the smooth waveguide against analytical solutions for wave impedance, propagation constant, and S-parameters. Results show that the FDTD model is in agreement with the analytical solution for the smooth waveguide and is a reasonable approximation of the stochastic scattering loss for the rough waveguide.