Self-consistent solutions for allowed interconnect current density. I. 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/sub peak/ as a function of wave shape. The maximum allowed temperature and j/sub 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/sub 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/sub peak/ will have to come at some future time from technology options which lower the temperatures at which the interconnects operates.