Life time characterization for a highly robust metallization

For mixed signal applications it is necessary to have metallization which are able to carry high currents. Also the on chip integration leads to special requirements on the metallization concerning their robustness. A common method for the determination of interconnect lifetime is described in JP001A and based on Black´s law and the measurement of time to failure, medium stress current density and medium stress temperature. The highly robust metallization presented here, which was developed for higher current and temperature applications shows more complicated shapes than presently used metallization systems with metal line tracks and via. To determine a realistic life time of highly robust metallization the used method is not applicable anymore. A more suitable determination of the variables current density and temperature for AlCu metallization with W-plug can be achieved by simulations. In the metal line layout the most critical locations regarding mass flux are chosen. The results are validated by measurements.