Large Reaction Rate Enhancement in Formation of Ultrathin AuSi Eutectic Layers

Tyler S. Matthews, Carolyn Sawyer, D. Frank Ogletree, Zuzanna Liliental-Weber, Daryl C. Chrzan, and Junqiao Wu

Phys. Rev. Lett. 108, 096102 – Published 1 March 2012

Abstract

Metal-semiconductor eutectic liquids play a key role in both the fundamental understanding of atomic interactions and nanoscale synthesis and catalysis. At reduced sizes they exhibit properties distinct from the bulk. In this work we show an unusual effect that the formation of AuSi eutectic liquid layers is much easier for smaller thicknesses. The alloying reaction rate is enhanced by over 20 times when the thickness is reduced from 300 to 20 nm. The strong enhancement is attributed to a strain-induced increase in the chemical potential of the solid layer prior to the alloying reaction.

Received 28 November 2011

DOI:https://doi.org/10.1103/PhysRevLett.108.096102

Authors & Affiliations

Tyler S. Matthews^1,2, Carolyn Sawyer^1,2, D. Frank Ogletree³, Zuzanna Liliental-Weber², Daryl C. Chrzan^1,2, and Junqiao Wu^1,2,*

¹Department of Materials Science & Engineering, University of California, Berkeley, California 94720, USA
²Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA
³The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA