Abstract
A comprehensive study on the growth of nanoscale transition metal-on-transition metal (TM-on-TM) systems is presented. The near room-temperature intermixing and segregation phenomena during growth are studied in vacuo using high-sensitivity low-energy ion scattering. The investigated TM-on-TM systems are classified into four types according to the observed intermixing and segregation behavior. Empirical rules are suggested to qualitatively predict the growth characteristics of any TM-on-TM system based on the atomic size difference, surface-energy difference, and enthalpy of mixing between the film and substrate atoms. An exponential trend is observed in the effective interface width as a function of the surface-energy difference between the film and substrate layers, with a subtrend based on the crystal structure of the TM layers. A semiempirical model that accurately describes the experimental data is presented. It serves as a scaling law to predict the effective interface width and the minimum film thickness required for full film coverage in TM-on-TM systems in general. The ability to predict the growth characteristics as well as the interface width for any TM-on-TM system significantly contributes to the process of finding the best material combination for a specific application, where layer growth characteristics are implicitly considered when selecting materials based on their functional properties.
Original language | English |
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Pages (from-to) | 46311−46326 |
Number of pages | 16 |
Journal | ACS applied materials & interfaces |
Volume | 11 |
Issue number | 49 |
Early online date | 15 Nov 2019 |
DOIs | |
Publication status | Published - 11 Dec 2019 |
Keywords
- UT-Hybrid-D
- sputter deposition
- interfaces
- scaling law
- transition metals
- low energy ion scattering
- intermixing
- thin film growth
- segregation