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. The authors have measured the principal strain state of Al alloy lines passivated with silicon nitride directly as a function of temperature. They compare these results with calculations of the strain state in these lines using finite-element modeling. The measured strain-temperature behavior shows food 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.