Atomic Layer Deposition of Ru Thin Film Using a Newly Synthesized Precursor with Open‐Coordinated Ligands
Seung Hoon Oh, Jeong Min Hwang, Hyeonbin Park, Dongseong Park, Young Eun Song, Eun Chong Ko, Tae Joo Park, Taeyong Eom, Taek‐Mo Chung
Abstract
Abstract Ru films are grown on Pt, TiN, and SiO 2 substrates via atomic layer deposition (ALD) using Ru(II)(η 5 ‐C 7 H 7 O)(η 5 ‐C 7 H 9 ) as the novel Ru metalorganic precursor and O 2 as the reactant. The ALD self‐limiting film growth is confirmed at the low temperature of 200 °C by manipulating the injection time and purge time of the Ru precursor and O 2 , and the saturated growth per cycle is 0.22 Å cy −1 . It is confirmed that the combustion reaction occurs during the deposition process from the formation of the H 2 O and CO 2 by‐products. Thin films with a low resistivity of 17–19 µΩ cm are grown at a thickness of ≈15 nm. The Ru incubation times are remarkably short at 200 °C (negligible on Pt, ≈30 cycles on TiN and SiO 2 ), but increase with increasing temperature. The energy dispersive X‐ray mapping image of the Ru film on the pattern in which TiN is formed on SiO 2 shows that the Ru film with a novel precursor has the intrinsic substrate selectivity at the deposition temperature of 300 °C. Furthermore, the substrate affects the properties of the Ru film. Particularly because Ti serves as an oxygen reservoir, a relatively large amount of RuO x is produced on the TiN substrate.