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Title: Effect of the nature of the substrate on the surface chemistry of atomic layer deposition precursors

The thermal chemistry of Cu(I)-sec-butyl-2-iminopyrrolidinate, a promising copper amidinate complex for atomic layer deposition (ALD) applications, was explored comparatively on several surfaces by using a combination of surface-sensitive techniques, specifically temperature-programmed desorption and x-ray photoelectron spectroscopy (XPS). The substrates explored include single crystals of transition metals (Ni(110) and Cu(110)), thin oxide films (NiO/Ni(110) and SiO 2/Ta), and oxygen-treated metals (O/Cu(110)). Decomposition of the pyrrolidinate ligand leads to the desorption of several gas-phase products, including CH 3CN, HCN and butene from the metals and CO and CO 2 from the oxygen-containing surfaces. In all cases dehydrogenation of the organic moieties is accompanied by hydrogen removal from the surface, in the form of H 2 on metals and mainly as water from the metal oxides, but the threshold for this chemistry varies wildly, from 270 K on Ni(110) to 430 K on O/Cu(110), 470 K on Cu(110), 500 K on NiO/Ni(110), and 570 K on SiO 2/Ta. Here, copper reduction is also observed in both the Cu 2p 3/2 XPS and the Cu L 3VV Auger (AES) spectra, reaching completion by 300 K on Ni(110) but occurring only between 500 and 600 K on Cu(110). On NiO/Ni(110), both Cu(I) and Cu(0) coexistmore » between 200 and 500 K, and on SiO 2/Ta a change happens between 500 and 600 K but the reduction is limited, with the copper atoms retaining a significant ionic character. Additional experiments to test adsorption at higher temperatures led to the identification of temperature windows for the self-limiting precursor uptake required for ALD between approximately 300 and 450 K on both Ni(110) and NiO/Ni(110); the range on SiO 2 had been previously determined to be wider, reaching an upper limit at about 500 K. Finally, deposition of copper metal films via ALD cycles with O 2 as the co-reactant was successfully accomplished on the Ni(110) substrate.« less
Authors:
 [1] ;  [2] ;  [2] ;  [1]
  1. Univ. of California, Riverside, CA (United States). Dept. of Chemistry
  2. Carleton Univ., Ottawa, ON (Canada). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
FG02-03ER46599; SC0001839
Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 146; Journal Issue: 5; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Research Org:
Univ. of California, Riverside, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1474074
Alternate Identifier(s):
OSTI ID: 1330595

Yao, Yunxi, Coyle, Jason P., Barry, Seán T., and Zaera, Francisco. Effect of the nature of the substrate on the surface chemistry of atomic layer deposition precursors. United States: N. p., Web. doi:10.1063/1.4966201.
Yao, Yunxi, Coyle, Jason P., Barry, Seán T., & Zaera, Francisco. Effect of the nature of the substrate on the surface chemistry of atomic layer deposition precursors. United States. doi:10.1063/1.4966201.
Yao, Yunxi, Coyle, Jason P., Barry, Seán T., and Zaera, Francisco. 2016. "Effect of the nature of the substrate on the surface chemistry of atomic layer deposition precursors". United States. doi:10.1063/1.4966201. https://www.osti.gov/servlets/purl/1474074.
@article{osti_1474074,
title = {Effect of the nature of the substrate on the surface chemistry of atomic layer deposition precursors},
author = {Yao, Yunxi and Coyle, Jason P. and Barry, Seán T. and Zaera, Francisco},
abstractNote = {The thermal chemistry of Cu(I)-sec-butyl-2-iminopyrrolidinate, a promising copper amidinate complex for atomic layer deposition (ALD) applications, was explored comparatively on several surfaces by using a combination of surface-sensitive techniques, specifically temperature-programmed desorption and x-ray photoelectron spectroscopy (XPS). The substrates explored include single crystals of transition metals (Ni(110) and Cu(110)), thin oxide films (NiO/Ni(110) and SiO2/Ta), and oxygen-treated metals (O/Cu(110)). Decomposition of the pyrrolidinate ligand leads to the desorption of several gas-phase products, including CH3CN, HCN and butene from the metals and CO and CO2 from the oxygen-containing surfaces. In all cases dehydrogenation of the organic moieties is accompanied by hydrogen removal from the surface, in the form of H2 on metals and mainly as water from the metal oxides, but the threshold for this chemistry varies wildly, from 270 K on Ni(110) to 430 K on O/Cu(110), 470 K on Cu(110), 500 K on NiO/Ni(110), and 570 K on SiO2/Ta. Here, copper reduction is also observed in both the Cu 2p3/2 XPS and the Cu L3VV Auger (AES) spectra, reaching completion by 300 K on Ni(110) but occurring only between 500 and 600 K on Cu(110). On NiO/Ni(110), both Cu(I) and Cu(0) coexist between 200 and 500 K, and on SiO2/Ta a change happens between 500 and 600 K but the reduction is limited, with the copper atoms retaining a significant ionic character. Additional experiments to test adsorption at higher temperatures led to the identification of temperature windows for the self-limiting precursor uptake required for ALD between approximately 300 and 450 K on both Ni(110) and NiO/Ni(110); the range on SiO2 had been previously determined to be wider, reaching an upper limit at about 500 K. Finally, deposition of copper metal films via ALD cycles with O2 as the co-reactant was successfully accomplished on the Ni(110) substrate.},
doi = {10.1063/1.4966201},
journal = {Journal of Chemical Physics},
number = 5,
volume = 146,
place = {United States},
year = {2016},
month = {11}
}

Works referenced in this record:

Atomic Layer Deposition: An Overview
journal, January 2010
  • George, Steven M.
  • Chemical Reviews, Vol. 110, Issue 1, p. 111-131
  • DOI: 10.1021/cr900056b