Stress-voiding of narrow conductor lines

The growth of voids in conductor lines that have no applied voltage nor imposed thermal or concentration gradients is examined. Such voids can cause narrow aluminium conductors in silicon ICs to fail spontaneously. Recent attempts to describe void growth mathematically as a stress-driven diffusive phenomenon are reviewed, and an expression for the time dependent void size is derived. The equation is used to explore the many variables of the void-growth problem.<>