Atomic layer deposition of Ru/RuO2Thin films studied by in situ infrared spectroscopy

Park, SK; Kanjolia, R; Anthis, J; Odedra, R; Boag, NM; Wielunski, L; Chabal, YJ

Abstract

The deposition of ruthenium thin films is investigated using a newly synthesized precursor
(cyclopentadienyl ethylruthenium dicarbonyl, Ru(Cp)(CO)2
Et) and O2 gas as reactants. The conditions to achieve self-terminated surface reactions (sample temperature, precursor pulse length and
precursor gas pressure) are investigated and the resulting composition, conductivity, and surface
morphology are determined during/after deposition on hydrogen-terminated silicon (111) surfaces
using in situ FTIR, and ex situ Rutherford back scattering, X-ray photoelectron spectroscopy, and
atomic force microscopy. Higher growth rates (∼1.5-3 A˚
) are obtained compared to those typical of
ALD of metals (∼0.5-1 A˚
), under conditions of saturation, i.e., through self-terminated surface
reactions. Infrared absorption measurements reveal that bridged CO formed by the self-reaction of
Ru(Cp)(CO)2
Et leads to surface passivation, thus terminating the precursor self-reaction. They also
show that, under these “saturation” growth conditions, metallic Ru develops during the early stage of
deposition (1-5 cycles), and RuO2 is observed later in the growth. The deposition rate is linear with
cycles after an initially slow nucleation stage and the film becomes metallic after∼22 cycles. Thick films
(∼45 nm) grown with short pulses produce metallic polycrystalline ruthenium with hcp structure.

Citation

Park, S., Kanjolia, R., Anthis, J., Odedra, R., Boag, N., Wielunski, L., & Chabal, Y. (2010). Atomic layer deposition of Ru/RuO2Thin films studied by in situ infrared spectroscopy. Chemistry of Materials, 22(17), 4867-4878. https://doi.org/10.1021/cm903793u

• Journal Article Type: Article
• Publication Date: Jan 1, 2010
• Deposit Date: Nov 6, 2014
• Journal: Chemistry of Materials
• Print ISSN: 0897-4756
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Issue: 17
• Pages: 4867-4878
• DOI: https://doi.org/10.1021/cm903793u
• Publisher URL: http://dx.doi.org/10.1021/cm903793u
• Related Public URLs: http://pubs.acs.org/journal/cmatex
• Additional Information: Funders : Funder not known