MICROSTRUCTURE MAPPING OF INTERCONNECTS BY ORIENTATION IMAGING MICROSCOPY

Orientation imaging microscopy (OIM) provides a detailed description o f the variation in crystallographic structure over the surface of sing le crystal or polycrystalline bulk materials. This technique has been used in the investigation of interconnect lines and contact pad materi al in a number of aluminum metallizations on silicon oxide/silicon sub strates. The specimens were examined in a scanning electron microscope fitted with apparatus for collecting electron back-scatter diffractio n patterns (EBSPs). OIM scans were performed over various regions of e ach specimen. The technique has provided information regarding the loc al texture variations between different regions of a thin film structu re for both patterned and unpatterned metallizations. It was concluded that significant modification of the microstructure may occur subsequ ent to the initial metal deposition and that this modification can dif fer between the unpatterned regions and interconnect lines of varying widths.