In the present study, the Eshelby theory of inclusions is applied to model the stresses arising after heat treatment at 400 °C in aluminum line metallizations, embedded in silicon/passivation matrix. The stresses obtained are about 200 MPa higher than the ones previously reported. Moreover, the stresses in the axial and width directions of the lines are shown to be on the same order, while the normal stress is smaller, especially in the lines of low thickness-to-width ratio. A modification of the familiar sin2 ψ method of x-ray stress measurement is presented to deal more accurately with the [111]-fiber texture present in the aluminum lines studied. The lateral and normal stresses in the aluminum metallizations after a heat treatment at 400 °C are measured in room temperature by x-ray diffraction from 4 h after the heat treatment at 400 °C up to 3 months. The experimental results are well in accord with predictions obtained from the Eshelby model. Particularly, the lateral stresses are found to be about equal, while the initial normal stress is smaller, but eventually becomes the largest stress component. Dislocation mechanisms to rationalize the present observations are discussed: at longer times, diffusion-controlled dislocation climb and void growth connected to it appear to be the most important mechanisms to relieve the stress, while during cooling dislocation glide is also significant.

Indentation load relaxation (ILR) experiments with indentation depths in the submicron range are described. Under appropriate conditions, the ILR data are found to yield flow curves of the same shape as those based on conventional load relaxation data. Variations in flow properties as a function of depth in submicron metal films deposited on a hard substrate are detected by the experiments described.

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Grain boundary voiding and notching have been found to produce failures in narrow metallizations during thermal aging. The nucleation and growth of grain boundary voids are considered to occur as a result of grain boundary sliding and the subsequent stress-induced mass transport. A proposed model yields the linewidth and temperature dependence of the observed failure rate.

Grain boundary voiding has been identified as a diffusional creep mechanism that produces failure of narrow Al-based metallizations during thermal aging. It is considered to be a reliability concern for sub-micron metallizations because the resulting failure rate has been observed to be strongly line width dependent. This paper presents a theoretical model for stress-induced grain boundary voiding. The proposed model is shown to account for the experimentally observed temperature and time dependence of thermal aging-induced line failure data reported in the literature.