Silver carboxylates adducts, like f.e. Ag(PhCH2COO)(PbBu3)2, were considered as potential silver CVD precursors.
Ag(CH3COO)[P(nBu)3]m (m=1-4) adducts were studied by P31{H1} NMR spectroscopy at low temperature: m=1 (at -60°C), m=2 (at -80°C), m=3 (at -90°C), m=4 (at -95°C). (see Fig.)
The decomposition Ag(CH3COO)[P(nBu)3]m (m=1-4) adducts was studied by mass-spectroscopy. (Fig.) The precursor decomposes producing metallic slver, and can be potentially applied as Ag MOCVD precursor.
Phosphine stabilized silver (I) complexes, namely bis(tris-n-butylphosphine) silver 2-methyl-but-2-enate Ag(nBu3P)2(MeCH=C(Me)COO) has been evaluated for the deposition of silver
thin films by CVD. Silver films with good resistivity of 11.2 µΩ*cm have been deposited. [[i]]
[i] http://pc1.uni-bielefeld.de/~naoufal/CVD%20precursors.html
Properties: Colorless prisms (triclinic crystalline structure). Sublimates with heavy losses. Freely soluble in water, ether and benzene, slightly soluble in chloroform.
Synthesis:
method 1 [5a, 5b]: NaCF3COO + AgNO3 => AgCF3COO + NaNO3
Saturated sodium trifluoroacetate solution was added dropwise to concentrated silver nitrate solution. The solution was filtered to remove traces of silver chloride. Ether is used to extract the major part of AgCF3COO overnight with ether. Evaporation of the solution in a water bath and re-extraction with ether yielded the product (after evaporation the ethereal extract to dryness.)
Method 2: Addition of Ag2O to 50% aqueous CF3COOH solution and evaporation in vacuo. [5c]
Ag film CVD
The CVD process with these three precursors was optimized using thermodynamic calculations using a modified SOLGASMIX-PV computer program. With Ag (PF), high quality silver films at low temperatures
and pressures were obtained. The fibrous wire having a silver barrier layer and a top layer of YBa2Cu3Ox exhibited superconductivity at 72 K. [[i]]
[i] Shapiro M.J., Lackey W.J., Hanigofsky J.A., Hill D.N., Carter W.B., Barefield E.K. Chemical Vapor Deposition of Silver Films for Superconducting Wire Applications, Journal of Alloys and Compounds, 1992, Vol.187, Iss.2, pp.331-349.
Silver pivalate trialkylphoshine adducts [Ag(O2CtBu)(PMe3)] (1) and [Ag(O2CtBu)(PEt3)] (2) were applied as CVD precursors. 30-100nm thin Ag layers were deposited on Si(111)
and Si(100) substrates using hot-wall and cold-wall CVD techniques in the temperature range 180-220 °C, under the reactor pressure 1–3 mbar. Metallic films were characterized by XRD, XPS), glow discharge optical emission spectroscopy
(GDOES), SEM and conductivity measurements.[[i]]
[i]P. Piszczek, E. Szłyk, M. Chaberski, C. Taeschner, A. Leonhardt, W. Bała, K. Bartkiewicz, Chemical Vapor Deposition,Volume 11, Issue 1, pages 53–59, January, 2005 , “Characterization of Silver Trimethylacetate Complexes with Tertiary Phosphines as CVD Precursors of Thin Silver Films”