Investigation of growth mechanisms during the deposition and oxidation of Ir and Ru based thin films*

The reliable growth of phase-pure platinum group metal thin films has been of recent interest due to the group’s tendencies toward high conductivity and corrosive resistance. Ir and Ru have been studied as favorable candidates for interconnects in microelectronics¹ and catalytic materials for green hydrogen production.² Several ruthenate and iridate oxides have also been studied for their unique magnetic and electrical properties.³ Film quality often dictates the performance of these materials and is controlled by the growth machanism and conditions of synthesis. In this work, we examined the thermodynamic driving forces underlying the synthesis of elemental Ir and Ru thin films grown by solid source metal-organic molecular beam epitaxy (SSMOMBE).⁴ In combination with experimental efforts, we aimed to understand the significance of these driving forces in governing metal (Ru, Ir) vs. oxide (RuO₂, IrO₂) formation during SSMOMBE growth. This work has the potential to be expanded to ternary systems of interest, which may further our understanding of the underlying driving forces governing film synthesis.

 

(1)       Wen, L. G.; et. al., ACS Appl. Mater. Interfaces 2016, 8 (39), 26119–26125.

(2)       Basińska, A.; et. al., React. Kinet. Catal. Lett. 2006, 89 (2), 319–324.

(3)       Koster, G.; et. al., Rev. Mod. Phys. 2012, 84 (1), 253–298.

(4)       Nair, S.; et. al., J. Vac. Sci. Technol. A 2023, 41 (6), 062701.