Self-consistent solutions for allowed interconnect current density .1. Implications for technology evolution

We comprehend both interconnect electromigration and Joule heating to study for the first time the self-consistent solutions for the maximum allowed interconnect peak current density j(peak) as a function of wave shape. The maximum allowed temperature and j(peak) solutions monotonically increase as the duty cycle r decreases. Self-consistent solutions indicate that there are diminishing returns in the usefulness of increasing the electromigration capability of the interconnect system. While the greatest increase in allowed j(peak) occurs at de stress (r = 1), the increases becomes less as r is reduced below 1, and becomes negligible for r < 0.01. Further increases in j(peak) will have to come at some future time from technology options which lower the temperatures at which the interconnects operates.