【摘要】 将晶核析出的Avrami方程应用于描述超大规模集成电路中金属Al薄膜互连电迁移过程中电阻的演变.根据电子散射理论,晶界电阻主要起源于晶界处空位或者空洞对电子的散射.为了描述这些离子的特征,引入了自由体积的概念,将晶界处电子散射这个复杂的过程简化用自由体积的有效散射截面来描述,从而建立了自由体积与电阻变化的定量关系,统一描述了电迁移过程中不同阶段的电阻变化.数值模拟结果表明,在第一个空洞成核时刻电阻会发生急剧变化,这一结果已被实验所证实.更多还原

【Abstract】 A well_known model for the rate of heterogeneous nucleation and growth of a second_phase precipitate in a solid matrix has successfully been applied to analyze the electromigration process in Al thin_film interconnects. The change of resistance is considered resulting mainly from the scattering of electrons by atoms around the vacancies or voids at grain boundaries. Free volume is introduced to describe the behavior of these atoms and to simplify the complicated scattering process by means of the effective scattering cross section of the free volume. The quantitative relation between the scattering cross section and the resistance change is established, and from which the resistance revolution can be characterized during different electromigration stages. Comparison of our simulation results with experimental data shows good agreement and our model can explain the previously unexplained abrupt resistance change phenomena.更多还原