FINITE-ELEMENT MODELING AND X-RAY-MEASUREMENT OF STRAIN IN PASSIVATED AL LINES DURING THERMAL CYCLING

Narrow-pitch encapsulated Al lines are used as interconnect metallization in integrated circuits. We have measured the principal strain state of Al alloy lines passivated with silicon nitride directly as a function of temperature. We compare these results with calculations of the strain state in these lines using finite-element modeling. The measured strain-temperature behavior shows good fundamental agreement with finite-element modeling, although the magnitude of the strains measured with x-rays is less than that predicted by modeling due to voiding in the lines.