ALD/MLD processes for Mn and Co based hybrid thin films

Abstract

Here we report the growth of novel hybrid transition metal-organic thin-film materials consisting of manganese or cobalt as the metal component and terephthalate as the rigid organic backbone. The hybrid thin films are deposited by the currently strongly emerging atomic/molecular layer deposition (ALD/MLD) technique using the combination of metal β-diketonate, i.e. Mn(thd)3, Co(acac)3 or Co(thd)2, and terephthalic acid (1,4-benzenedicarboxylic acid) as precursors. All the processes yield homogeneous and notably smooth amorphous metal-terephthalate hybrid thin films with growth rates of 1-2 Å/cycle.The films are stable towards humidity and withstand high temperatures up to 300 or 400 °C under oxidative or reductive atmosphere, respectively. The films are characterized with XRR, AFM, GIXRD, XPS and FTIR techniques.

Iron-Terephthalate Coordination Network Thin Films Through In-Situ Atomic/Molecular Layer Deposition

“…Amorphous Fe-TP films resulted also from the depositions based on the Fe(acac) 3 precursor, in this case within the entire deposition temperature range investigated. Recalling also our previous work on Co-TP and Mn-TP depositions yielding amorphous films from both acac and thd metal precursors 21 , we conclude that the steric hindrance caused by the bulky ligands apparently complicates the building-up of the new coordination bonds and thereby the coordination network structure. This provides important guidelines for the in-situ gas-phase deposition of transition-metal based coordination network thin films – a target of great future demand.…”

“…Transition metals with partly filled d orbitals and less electropositive nature prefer directional covalent bonds. Most of the ALD/MLD processes for transition metals have yielded amorphous films 17 – 21 , the only exceptions being the ALD/MLD processes for copper 7 and zirconium 22 , 23 based on Cu(thd) 2 (thd: 2,2,6,6-tetramethyl-3,5-heptanedione) plus TPA (TPA: terephthalic acid or 1,4-benzene dicarboxylic acid), ZrCl 4 plus TPA and ZrCl 4 plus 2-amino derivative of TPA. Note, however, that in the latter case an additional post-deposition treatment was required to crystallize the films.…”

Structurally Stable Manganese Alkoxide Films Grown by Hybrid Molecular Layer Deposition for Electrochemical Applications

“…In the first, Abdulagatov et al briefly mentioned the synthesis of a manganese hybrid film during an investigation of the pyrolysis of a variety of other hybrid materials grown by MLD. In the second, Ahvenniemi and Karppinen synthesized a manganese hybrid film using tris(2,2,6,6‐tetramethyl‐3,5‐heptanedionato)manganese and terephthalic acid. However, only a characterization of its synthesis was reported and no application was explored in that work.…”

Atomic and Molecular Layer Deposition of Hybrid Mo–Thiolate Thin Films with Enhanced Catalytic Activity

“…The incorporation of both ALD and MLD chemistries into a blended ALD/MLD process enables the creation of hybrid materials with both organic and inorganic components . Thus far, hybrid chemistries based on ALD/MLD have been reported for films containing metals such as Fe, Al, Mn, Co, Ti, Zn, and Zr, and the resultant films were found to have a variety of interesting electrical, magnetic, and catalytic properties. The exploration of new ALD/MLD chemistries and the unique inorganic–organic thin films that such processes may form are therefore of interest both for fundamental insights into the reaction chemistry and for potential, wide‐ranging applications such as HER catalysis.…”