金属互连电迁移噪声的非高斯性模型研究

摘要

Based on scattering theory, the resistance of polycrystalline interconnection originates mainly from vacancies and voids scattering at grain boundary. Through using the free volume concept, the scattering process at grain boundary is simulated, and a non-Gaussian model of noise is establised. The model shows the earlier electromigration noise is gaussian, through electromigration process, noise turns non-Gaussian, which reflects the change of dynamic mechanism. Bicoherence coefficient is used to characterize the non-Gaussian noise. Finally, experimental result validates the model.%根据电子散射理论，多晶互连中，电阻主要起源于晶界处空位与空洞对电子的散射作用．通过引入自由体积的概念，模拟了晶界处电子的散射过程，建立了基于自由体积的噪声非高斯性表征模型．该模型表明，电迁移前期的噪声信号以高斯噪声为主，随电迁移过程将发生噪声信号从高斯性向非高斯性的突变，表明噪声产生机制发生了转变，并通过双相干系数对信号的非高斯性进行了定量表征．最终，通过实验初步证明了理论结果的正确性．