The present work demonstrates an electroless (e-less) deposition of Pb monolayer on Au and Cu surface whose morphology and properties resemble its underpotentially deposited counterpart. Our results and analysis show that the e-less Pb monolayer deposition is a surface selective, surface controlled, self-terminating process. Results also show that the electroless Pb monolayer deposition is enabling a phenomenon for new deposition method called "electroless atomic layer deposition" (e-less ALD). Here, the e-less Pb monolayer serves as reducing agent and sacrificial material in surface limited redox replacement reaction with noble metal ions such as Pt , i.e., Pt deposition. The e-less ALD is highly selective to the metal substrates at which Pb forms the e-less monolayer. The full e-less ALD cycle leads to an overall deposition of a controlled amount of the noble metal. Repetition of the two-step e-less ALD cycle an arbitrary number of times leads to formation of a highly compact, smooth, and conformal noble metal thin film with applications spanning from catalyst synthesis to semiconductor technology. The process is designed for (but not limited to) aqueous solutions that can be easily scaled up to any size and shape of the substrate, deeming its wide applications.

An alkaline, tartrate-complexed copper electrolyte containing additives that provide bottom-up fill is described. Bottom-up fill is achieved using a mixture of two additives: bis-(3-sulfopropyl) disulfide (SPS) and polyethyleneimine (PEI). Chronopotentiometric studies indicate that, unlike in conventional acidic electrolytes, SPS acts as a 'suppressor' and PEI acts as an 'anti-suppressor' in the alkaline medium. Partial-fill experiments on patterned structures confirm a SPS-PEI interaction leading to bottom-up fill from the tartrate-complexed copper electrolyte.

We present results exploring different concepts for Pb monolayer mediated thin film growth of Cu on Ru(0001) and Co on polycrystalline Cu substrates. Both systems are of considerable importance in microchip fabrication technology and they exhibit a three dimensional growth at room temperature which somewhat limits their application. The Pb monolayer mediation of the growth process is explored by having its role as a surfactant, flux mediator or as a sacrificial layer in deposition via surface limited redox replacement protocol. Electrochemical and STM results suggest that Pb monolayer induces 2D Cu growth on Ru(0001) and the growth mechanism is very dependent on the Pb mediation role. The surfactant properties of electrolessly deposited Pb monolayer are also studied during electroless deposition of Co on polycrystalline Cu. The benefit of Pb monolayer mediation of the Co growth process was manifested by 2D Co thin film morphology, high quality of the grain boundaries, and improved magnetic properties.

The work reporting a detailed and comparative study of Pb UPD and Pb e-less ML deposition on Ru(0001) substrate is presented. The electrochemical results are analyzed through the scope of the adsorption isotherm formalism where parameters describing the thermodynamics of deposited Pb monolayer obtained by each process are compared. In addition to these results, the in situ STM and electrochemical quartz micro balance data are presented for each process identifying the mutual mechanistic similarities and differences between electroless Pb and underpotential Pb monolayer. Considerable applications of Ru metal in microelectronics and catalysis rise significance of these results for variety of future developments in these areas.

Electrodeposition of copper germanide (Cu3Ge) thin films from an alkaline tartrate-complexed electrolyte is described. Current pulsing is shown to enable co-deposition of copper and germanium in the stoichiometric ratio Cu:Ge = 3:1, while providing smooth and compact electrodeposits. The presence of ε-Cu3Ge phase with a monoclinic crystal structure is confirmed by X-ray diffraction of the as-deposited films. After annealing, Cu3Ge films exhibit an electrical resistivity of 45 μΩ cm; a value higher than previously reported resistivity of e-beam evaporated Cu3Ge films (∼10 μΩ cm). The higher electrical resistivity of the electrodeposited Cu3Ge films is attributed to smaller grain size and elevated impurity levels.