A1 Journal article (refereed)
Reaction Pathways for Atomic Layer Deposition with Lithium Hexamethyl Disilazide, Trimethyl Phosphate, and Oxygen Plasma (2020)


Werbrouck, A., Mattelaer, F., Minjauw, M., Nisula, M., Julin, J., Munnik, F., Dendooven, J., & Detavernier, C. (2020). Reaction Pathways for Atomic Layer Deposition with Lithium Hexamethyl Disilazide, Trimethyl Phosphate, and Oxygen Plasma. Journal of Physical Chemistry C, 124(50), 27829-27839. https://doi.org/10.1021/acs.jpcc.0c09284


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Publication details

All authors or editors: Werbrouck, Andreas; Mattelaer, Felix; Minjauw, Matthias; Nisula, Mikko; Julin, Jaakko; Munnik, Frans; Dendooven, Jolien; Detavernier, Christophe

Journal or series: Journal of Physical Chemistry C

ISSN: 1932-7447

eISSN: 1932-7455

Publication year: 2020

Volume: 124

Issue number: 50

Pages range: 27829-27839

Publisher: American Chemical Society (ACS)

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1021/acs.jpcc.0c09284

Publication open access: Not open

Publication channel open access:


Abstract

Atomic layer deposition (ALD) of lithium-containing films is of interest for the development of next-generation energy storage devices. Lithium hexamethyl disilazide (LiHMDS) is an established precursor to grow these types of films. The LiHMDS molecule can either be used as a single-source precursor molecule for lithium or as a dual-source precursor molecule for lithium and silicon. Single-source behavior of LiHMDS is observed in the deposition process with trimethylphosphate (TMP) resulting in the deposition of crystalline lithium phosphate (Li3PO4). In contrast, LiHMDS exhibits dual-source behavior when combined with O2 plasma, resulting in a lithium silicate. Both processes were characterized with in situ ellipsometry, in situ time-resolved full-range mass spectrometry, X-ray photoelectron spectroscopy (XPS), and elastic recoil detection analysis (ERDA). When we combined both reactants into a three-step LiHMDS-TMP-O2* or LiHMDS-O2*-TMP process, the dual-source nature of LiHMDS emerged again. By carefully combining our measurements, it is shown that film growth with LiHMDS (in combination with TMP and O2 plasma) is driven by dipole-driven self-saturated surface interactions combined with dissociative chemisorption. We show that when hydroxyl groups are present on the surface, silicon will be incorporated in the films. These insights benefit the general understanding of the behavior of the LiHMDS and TMP precursors and may facilitate their effective use in ternary or quaternary processes.


Keywords: atomic layer deposition; thin films; lithium


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Ministry reporting: Yes

Preliminary JUFO rating: 2


Last updated on 2021-09-06 at 08:09