A practical modeling for transient thermal characteristics of multilevel interconnects

In this study, intuitive is given on time-dependent thermal characteristics in multilevel interconnects subjected to carry either DC or pulsed-DC. FEM simulation is employed to model the propensity of temperature profile with respect to the variety of interconnects having different geometrical features in terms of metal width, metal height and distance between metal and Si substrate. Accordingly, a practical model that enables to prognosis temperature increase resulting from current-driven metal interconnects and temperature decrease after current carried along metal line stops is developed. It is found that a proposed model precisely predicts thermal transient arisen from metal interconnect, regardless of geometrical factors of metal dimension and location. In addition, transient thermal behavior of metal interconnects carrying pulsed DC with various frequencies is investigated. A circuit designer is required to adjust the maximum allowable current carried along metal interconnects according to the frequency of pulsed DC as well as geometrical dimensions of metal interconnects. Hence, robustness in circuit design even in the earlier stage of development phase can be accomplished for metal interconnects by suppressing electromigration and rupture caused by thermal transient.