Adsorption Processes during Electrochemical Atomic Layer Deposition of Gold
- Case Western Reserve Univ., Cleveland, OH (United States)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Electrochemical atomic layer deposition (e-ALD) technique offers a simple and effective "wet chemistry" approach enabling high-precision monolayer-by-monolayer deposition of metal films. The process of e-ALD of Au involves lead underpotential deposition (PbUPD) followed by its redox replacement by a Au monolayer. The time evolution of the deposit mass during "one-pot" Au e-ALD is known to exhibit a unique three-stage response that is presently not well understood. In this work, we probe this response using voltammetry, electrochemical quartz crystal microgravimetry (e-QCM), and chronoamperometry to unravel the underlying mechanistic events during Au e-ALD. Furthermore, the presence of adsorbed Au+3-ligand complex(es) (Au-L) on the Au surface is established. In stage I of e-ALD, this Au-L adsorbed layer is reduced to Au while a PbUPD adlayer is formed. In stage II, the PbUPD adlayer undergoes spontaneous surface-limited redox replacement by nobler Au under open-circuit conditions. Finally, in stage III, re-adsorption of the Au-L occurs on the newly deposited Au. Quantitative analysis of the deposit mass transients obtained under a variety of conditions provides an estimate of the Au-L mass and its molecular weight.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1837812
- Report Number(s):
- LLNL-JRNL-825881; 1040200
- Journal Information:
- Journal of the Electrochemical Society, Vol. 168, Issue 11; ISSN 0013-4651
- Publisher:
- IOP Publishing - The Electrochemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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