Solid state dewetting of thin plasmonic films under focused cw-laser irradiation

Journal Article · Thu Dec 21 04:00:00 UTC 2017 · Acta Materialia

DOI: https://doi.org/10.1016/j.actamat.2017.12.030 · OSTI ID:1416974

Abbott, William M. ^[1]; Corbett, Simon ^[1]; Cunningham, Graeme ^[1]; Petford-Long, Amanda ^[2]; Zhang, Sheng ^[3]; Donegan, John F. ^[1]; McCloskey, David ^[1]

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1. Trinity College Dublin, Dublin (Ireland). School of Physics, CRANN and AMBER
2. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division; Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
3. Argonne National Lab. (ANL), Argonne, IL (United States). Materials Science Division

Elevated temperatures and large thermal gradients are a significant source of component failure in microelectronics, and is the limiting factor in heat-assisted magnetic recording (HAMR). Here, we have investigated the effect of solid-state dewetting in Au thin films, as a function of local temperature, film thickness, and substrate adhesion. In this work, a localised temperature rise is induced in thin (≤ 50 nm) polycrystalline Au films on SiO₂ substrates via focused continuous-wave laser irradiation at 488 nm. The magnitude and distribution of the total temperature rise is measured using CCD-based thermoreflectance. This also allows a sensitive measurement of the temperature at which dewetting occurs, showing that for thin (≤ 50 nm) Au films without adhesion layers, rapid dewetting can occur at temperatures as low as 50° C. The time decay of the reflected light from the illuminating laser is used to monitor locally the dynamics of solid state dewetting. TEM diffraction analysis shows significant changes in the microstructure and crystallographic texture of the films as far as 10 µm away from the illuminated area. The use of a thin metallic adhesion layer (such as Ti or Cr) is shown to significantly improve the adhesion of the Au to the substrate and reduce the tendency towards dewetting, but does not entirely protect it from changes to the crystallographic texture.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; Science Foundation Ireland (SFI); Western Digital Technologies, Inc.
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1416974
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: C Vol. 145; ISSN 1359-6454
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English