An electrothermal model of interconnects based on a transmissionline network

In this paper, an electrothermal model is proposed for transient analysis of interconnects on CMOS integrated circuits excited by electrostatic discharge pulse. A thermal transmission-line network is established to model the thermal conduction in interconnect structure. The exact input impedance of the thermal network is obtained and then inverse fast Fourier transformation is used to predict transient thermal responses of interconnects. An iterative process is developed to include electrothermal effects that positive feedback occurs between the electrical and thermal behaviours of interconnects, which can impact the performance and reliability of circuits. It is shown that interconnect temperature and resistance will be underestimated if electrothermal effects and transmission line effects are ignored. Numerical results show that the proposed model is much more efficient at the cost of less than 1% error compared with thermal solver based on finite element method.