Enhanced selectivity of atomic layer deposited Ru thin films through the discrete feeding of aminosilane inhibitor molecules

Nanoscale interface engineering for solid oxide fuel cells using atomic layer deposition

“…The second characteristic is the linearity of the as-grown thin lm thickness as a function of the number of ALD cycles; this is due to the monolayer growth in each of the ALD process cycles and the thin lm growth by the monolayer stacking mechanism through cycle repetition. 20,21 Consequently, ALD allows for precise thickness control at the angstrom level through cycle count control. Lastly, the ALD growth rate in a specic temperature range is insensitive to the deposition temperature, which is a very important process variable for chemical vapor deposition (CVD).…”

Atomic Layer Deposition of Ruthenium Films Using Ruthenium Diketonates and O2, H2, or N2O: The Role of Ruthenium Etching

“…Many metalorganic precursors and process conditions have been explored for the ALD of thin ruthenium films, but no entirely satisfactory answers have been obtained yet. One puzzling aspect of the results published to date on this subject is the wide range of deposition rates measured. − In ALD, the chemical reaction used to grow the thin films is split into two or more complementary and self-limiting reactions to limit the extent of the deposition per ALD cycle to a monolayer or less. Instead, deposition rates as high as 2 Å/cycle have been reported for Ru, and in the low-end rates as low as 0.05 Å/cycle have been measured as well. , In this report, we present results from surface characterization experiments aimed to look at the individual chemistry of the two halves of the ALD cycle, with emphasis on using O 2 as the co-reactant (combined with Ru­(tmhd) 3 as the Ru metalorganic precursor) to better understand the reasons for the poor behavior of Ru ALD.…”

Advanced Atomic Layer Deposition: Ultrathin and Continuous Metal Thin Film Growth and Work Function Control Using the Discrete Feeding Method

“…In other words, DFM suppresses the screening effect that occurs during the precursor feeding, making the overall ALD reaction more efficient. 13,14 As a result, higher surface coverage can be obtained, even with the same amount of precursor as used in conventional ALD. Therefore, the initial nucleation density during the film growth can be improved, and thus, the continuity of the grown thin film can also be improved.…”

“…In this study, we demonstrated deposition of ultrathin (∼3 nm) and continuous high-quality Ru films through ALD with a discrete feeding method (DFM), called DF-ALD. DF-ALD is a modified ALD process that divides the precursor feeding step into several short steps and introduces cut-in purge steps in between. , DF-ALD increased nucleation density in the initial stage of thin film growth, resulting in reduced critical thickness (i.e., the minimum thickness for continuous thin film formation) to ∼3 nm. In addition, the physical density of the ultrathin film was improved, allowing the formation of a Ru thin film having excellent electrical properties.…”

“…As shown in Figure b, physisorbed precursors during the precursor feeding step are removed by the cut-in purge in DF-ALD, which unveils the screened surface reaction sites and allows them to react with subsequently injected precursors. In other words, DFM suppresses the screening effect that occurs during the precursor feeding, making the overall ALD reaction more efficient. , As a result, higher surface coverage can be obtained, even with the same amount of precursor as used in conventional ALD. Therefore, the initial nucleation density during the film growth can be improved, and thus, the continuity of the grown thin film can also be improved.…”