Crystal-plasticity based thermo-mechanical modeling of Al-components in integrated circuits

This study presents a series of numerical simulations using a three dimensional model assembly considering aluminum conductors sputtered on a silicon substrate, surrounded by an interlayer dielectric and covered by an aluminum metallization plate with passivation layer. Different conductor path geometries are investigated. The model assembly is loaded by a cyclic heat flow. The thermo-mechanical problem is solved utilizing the Abaqus/Standard solver in combination with a user-defined material routine which takes into account the microstructure and the grain orientation of the aluminum, heat flow, thermal expansion and temperature dependent material behavior. The development of stresses and strains within the interlayer dielectric and within the different conductor path geometries is investigated and compared with experimental results. Observations like surface roughening and crack initiation can be predicted qualitatively correct.