An improved TDDB lifetime model of copper interconnect

With the reduction of interconnect dimensions, time-dependent dielectric breakdown (TDDB) has become more important. An improved TDDB lifetime model is proposed according to a physics mechanism based on the model of Wen Wu, et al.. The TDDB lifetime temperature dependence obtained by the original model is contrary to the experimental data. The improved model presented here introduces a correctional factor and takes into account the effects of electric fields, temperature, and interconnect line spacing. The predictions of the new model regarding TDDB lifetime vs. temperature agree well with the previously published experimental data. The improved model has important implications for interconnect technology and design.