Grain Boundary Diffusion Characterized by AFM KPFM

Ana Baca, Michael Brumbach, Paul Vianco, David Scyrmgeour, Rebecca Cho

Sandia National Laboratories

Materials aging is a high-consequence failure mode in electronic systems. Such mechanisms can degrade the electrical properties of connectors, relays, wire bonds, and other interconnections. Lost performance will impact, not only that of the device, but also the function and reliability of next-level assemblies. The detection of changes to materials surfaces at the nanometer-scale resolution, provides a means to identify aging processes at their early stages before they manifest into latent failures that affect system-level performance and reliability.
The nanometer scale characterization technique of Frequency Modulated Kelvin Probe Force Microscopy (FM-KPFM) will be used to assess a preliminary diffusion study on thin metal films that undergo accelerated aging. The KPFM technique provides a relatively easy, non-destructive methodology that does not require high-vacuum facilities to obtain nanometer spatial resolution of surface chemistry changes and will be exercised in an effort to explore its capacity to map surface potential contrast caused by Cu diffusion in a manner that allows for a qualitative assessment of diffusion rate kinetics. Supporting data will be obtained from traditional techniques: Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS).

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.