L. A. Copeland, Texas Instruments, Tucson, AZ; M. Saran, Texas Instruments, Dallas, TX

Summary: This paper will cover a new mechanical cross-sectioning approach for Cu-Al bonding that produces an image clarity not yet demonstrated in published literature. A critical sequence of polishing, optimized basic slurry and stain, as well as correct imaging parameters to highlight the growth morphology of the intermetallics has been developed. A description of the results when utilizing these techniques to section and image Cu-Al bonds, both before and after prolonged aging of up to 4000hrs at 150¢ªC, a temperature commonly used to assess the reliability of the integrated circuits is presented.