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Electromigration-induced failure in metal interconnect constitutes a major reliability problem in the semiconductor industry. Recently, experimental techniques capable of probing grain orientation and stress with a spatial resolution compatible with the dimensions of the lines have emerged. White beam X-ray microdiffraction is particularly well suited to the in situ study of electromigration. The technique was used to probe microstructure in interconnects and recently unambiguously unveiled the plastic nature of the deformation induced by mass transport during electromigration in Al(Cu) interconnect lines even before macroscopic damage. The aim of the present research is to understand the complex dislocation structure arising from electromigration-induced plastic deformation by simulating the shape of the reflections and comparing them with the shape observed in the experimental data. We provide a first quantitative analysis of the dislocation structure generated in individual micron-sized Al grains during an in situ electromigration experiment. Custom software allows us to determine the orientation of the predominant dislocation network in each sample subgrain. [Copyright &y& Elsevier]

A recently developed differential-aperture X-ray microscopy (DAXM) technique provides local structure and crystallographic orientation with submicron spatial resolution in three-dimensions; it further provides angular precision of ∼0.01° and local elastic strain with an accuracy of ∼1.0×10−4 using microbeams from high brilliance third generation synchrotron X-ray sources. DAXM is a powerful tool for inter- and intra-granular studies of lattice distortions and lattice rotations on mesoscopic length scales of tenths of microns to hundreds of microns that are largely above the range of traditional electron microscopy probes. Nondestructive, point-to-point, spatially resolved measurements of local lattice orientations in bulk materials provide direct information on geometrically necessary dislocation density distributions through measurements of the lattice curvature in plastically deformed materials. This paper reviews the DAXM measurement technique and discusses recent demonstrations of DAXM capabilities for measurements of microtexture, local elastic strain, and plastic deformation microstructure. [Copyright &y& Elsevier]

X-ray microbeams have been used to perform nondestructive measurements of the local orientations and microstructure in single-crystal and grain-boundary regions in a columnar Al (0.2 wt.% Mg) tri-crystal deformed 20% in plane-strain. The measurements were made using a recently developed differential-aperture X-ray microscopy (DAXM) technique providing high angular resolution determinations of local orientations with micron 3-D spatial resolution using focused microbeams. The X-ray microbeam technique is described, three-dimensional spatially resolved pole-figures and lattice rotation distributions in single-crystal and grain-boundary regions are presented, and the potential of micron resolution 3-D X-ray structural microscopy for plastic deformation investigations is discussed. [Copyright &y& Elsevier]