BARIUM β-DIKETONATES

In the alkaline earth b-diketonates M(diket)2, especially with M = Ba, oligomerization occurs in the absence of neutral donor ligands because two bidentate diketonate ligands are not sufficient to saturate the coordination spheres of the large metal ions, what results in the compounds with. Such oligomers have very low vapor pressures, thermal decomposition can occur at higher temperatures required to achieve volatility, this issue is most pronounced in case of barium precursors. In the recent years it was searched for neutral donor ligands that can coordinate to the bis(diketonato)metal(II) fragment and stabilise monomeric species with higher vapor pressures. [4]

Barium hexafluoracetylacetonate pentaethylenglycol-ethyl-butyl-ether adduct Ba(hfac)2(PEB)

Barium bis(hexafluoracetylacetonate) pentaethyleneglycol-ethyl-butyl-ether adduct Ba(hfac)2(PEB) is highly volatile fluorinated Ba precursor. This complex contains an unsymmetrical polyether PEB as a neutral ligand. Ba(hfac)2(PEB) has a low melting point (71°C), and sublimes at 110–120°C/4 Torr at rate useful for CVD film growth.

Hydrated barium bis( 2,2,6,6-tetramethylheptane-1,3-dionate) Ba5(thd)9(OH)

Hydrated Ba(thd)2 Ba5(thd)9(OH) (olften incorrectly referred as Ba(thd)2(H2O)2 ),

Has been often used for MOCVD of Ba.contaning films, for example liquid injection MOCVD of YBa2Cu3O7-x layers. [Abrutis et al.]

Ba(hfac)2(PEB) (+Ti(OiPr)4,+N2O/O2) for BaTiO3 by MOCVD

(Ba(hfac)2∙pentaethyleneglycolethylbutylether(PEB) complex, combined with Ti(OiPr)4 and 80% N2O +20% O2 as oxidiser was employed for the MOCVD growth of epitaxial BaTiO3 thin films on MgO(100) substrates at 700°C in a rotating disk vertical reactor. The strong oxidant - mixture of 80% N2O and 20% O2 was used to facilitate BaTiO3 growth at the lower temperature and suppress BaF2 impurity phase formation. Phase pure (containing only BaTiO3{001} x-ray diffraction peak) layers were grown at 700°C. The FWHM of X-ray rocking curve of the BaTiO3 (002) peak was 0.82°. The in-plane epitaxy of cube-on-cube orientation was confirmed by the fourfold symmetry and coincident positions of the {110} peaks for both BaTiO3 film and MgO substrate. The Φ -scan FWHM of 1.05° was determine for the grown BaTiO3 films. The utilised BaTiO3 growth temperature using (Ba(hfac)2∙PEB/ Ti(OiPr)4 /80%N2O+20%O2 was lower than the temperatures used in most comparable BaTiO3 thermal MOCVD epitaxial growth processes.[i]

[i][i] A.M. Dhote, A.L. Meier, D.J. Towner, B.W. Wessels, J. Ni, T.J. Marks, J Vacuum Sci. Techn. B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena 2005, 23, 1674; https://doi.org/10.1116/1.1993621 , « Low temperature deposition of epitaxial BaTiO3 films in a rotating disk vertical MOCVD reactor « , https://avs.scitation.org/doi/abs/10.1116/1.1993621

Barium bis(hexafluoracetylacetonate) methylethylpentaglyme adduct Ba(hfac)2mep

A liquid precursor Barium bis(hexafluoracetylacetonate) methylethylpentaglyme adduct Ba(hfac)2mep, in combination with Ca(hexafluoroacetylacetonate)2(tetraglyme) and Cu(dpm)2, (dpm = dipivaloylmethanate), has been applied for MOCVD growth of BaCaCuO(F) films, which later applied for the formation of high quality superconducting Tl2Ba2Can-1CunO4+2n (n = 2.3) by an ex-situ anneal in the presence of Tl2O at temperatures from 820-900°C.[i]

[i] B.J. Hinds, D.B. Studebaker, J. Chen, R.J. McNeely, B. Han, J.L. Schindler, T.P. Hogan, C.R. Kannewurf and T.J. Marks , Proceedings of the Tenth European Conference on Chemical Vapour Deposition, J. Phys. IV France 05 (1995) C5-391-C5-406, DOI: 10.1051/jphyscol:1995546

“MOCVD Routes to Tl2Ba2Can-1CunO4+2nSuperconductor and Dielectric Insulator Thin Films”

http://hal.archives-ouvertes.fr/docs/00/25/39/08/PDF/ajp-jp4199505C546.pdf

Barium bis(2,2,6,6-tetramethylheptane-3,5-dionate) [Ba(thd)2]4

Barium bis(2,2,6,6-tetramethylheptane-3,5-dionate) anhydrous [Ba(thd)2]4

Barium bis(2,2,6,6-tetramethylheptane-3,5-dionate) Ba(thd)2, or more precisely tetramer [Ba(thd)2]4, due to its relatively high volatility and thermals stability, is an important precursor for MOCVD preparation of various Ba-containing films, such as BaPb(Mg,Nb)O, BaB2O4, as well as the ALD of BaS thin films.

Synthesis: Ba(thd)2 prepared in situ by passage of thdH vapor over Ba(OH)2 held at 350°C.

Ba(thd)2 for BaPb(Mg,Nb)O by MOCVD

Ba(thd)2 was used for the growth of BaxPb1-x(Mg0.33Nb0.66)O3) (Ba-PMN) on Si and Pt/Ti/SiO2/Si substrates by MOCVD using ultrasonic nebulization of precursor solution. Ba substitution to Pb site of PMN promotes the perovskite phase stabilization and reduces pyrochlore phase content which even in small quantities decreases the dielectric constant and ferroelectric or piezoelectric performance of the films. Optimal Ba substitution allowed to obtain pure perovskite phase Ba-PMN films having excellent crystallographic and ferroelectric properties. [211]

Ba(thd)2 for BaB2O4 by injection MOCVD

Ba(thd)2, in combination with and triisopropylborate, both dissolved in triglyme solvent , has been applied for the liquid injection MOCVD growth of thin films of beta barium borate β-BaB2O4 were grown on silicon (100) substrates by injection metal organic chemical vapour deposition. The films were characterized by optical microscopy, micro-Raman spectroscopy (showing an intense peak at 637 cm−1 that is the fingerprint of β-BBO).and XPS. The growth conditions were following: Ba(thd)2 (concentration 1×10−2 mol/l.., Solution composition (Ba:B molar ratio) 1: 2, Evaporator temperature 250 °C, argon flow, 190 sccm, oxygen flow, 10 sccm, total pressure 133 Pa (1 Torr), injector opening time, 1 ms. Injection frequency, 1 Hz. [[i]]

[i] S. Wersand-Quell, G. Orsal, P. Thévenin, A. Bath

Thin Solid Films, Volume 515, Issue 16, 4 June 2007, Pages 6507–6511

“ Growth of beta barium borate (β-BaB2O4) thin films by injection metal organic chemical vapour deposition”

http://www.sciencedirect.com/science/article/pii/S004060900601460X

Ba(thd)2 for BaS by ALD

Ba (thd)2 has been applied as precursor to for the ALD growth of BaS thin films at 300–350°C, with H2S as the sulfur source. [see 4]

Ba(thd)2(tetraglyme)

Barium bis(2,2,6,6-tetramethylheptane-3,5-dionate) tetraglyme adduct Ba(thd)2(tetraglyme)

Ba(thd)2(tetraglyme) for BaB2O4 by liquid delivery MOCVD

Ba(thd)2(tetraglyme) , in combnation with triisopropyl borate (BOiPr3), has been applied for the growth of BaB2O4 films by liquid delivery MOCVD on various substrates such as fused SiO2, sapphire, Pt, Si. The growth conditions have been optimized to reproducibly obtain layers with c axis normal to the substrtate. The precursors were transported to the reactor at 7 mmol/h by a liquid delivery system. On sapphire substrate films having best quality were grown at720 °Cwith aslight excess of boron in the precursorsolution. [[i][

Ba(hfac)2(PEB) (+Ti(OiPr)4,+H2O) for BaTiO3 by MOCVD

Epitaxial BaTiO3 thin have been prepared by MOCVD at substrate temperatures 700–800°C using Ba(hfac)2(PEB), and Ti(OiPr)4, H2O as coreactants. Adiidtion of H2O was essential to avoid the BaF2 impurities in the layer. [4]

Barium bis(2,2,6,6-tetramethylheptane-3,5-dionate) pentamethyldiethylenetriamine adduct Ba(thd)2(PMDETA)

Ba(thd)2 adduct wit pentamethyldiethylenetriamine Ba(thd)2(PMDETA) is volatile , and in combination with Sr(thd)2(PMDETA) and Ti(OiPr)4, Ti(OiPr)2(thd)2 or Ti(dmae)4 was applied as precursor for MOCVD of BST (BaSrTiO3) thin films.

Ba(thd)2(PMDETA) for (Ba,Sr)TiOx by liquid injection MOCVD

Ba(thd)2(PMDETA) (PMDETA=pentamethyldiethylenetriamine)) was applied as Ba precursor (combined with Ti(dmae)4 (dmae=dimethylaminoethoxide) and Sr(thd)2-PMDETA) for the deposition of barium strontium titanate (Ba,Sr)TiOx (BST) thin films by direct liquid injection MOCVD.The incorporation of Ba and Sr into the BST film was almost constant (Ba/(Ba+Sr)=0.5) at growth temperatures 420–500 °C. The amount of Ti incorporation was substantially higher and the morphology much better (absence of hump and hazy appearance) with Ti(dmae)4 as Ti precursor for BST growth compared to Ti(OiPr)2(thd)2 or Ti(thd)2(mpd) (mpd = methylpentanediol). The step coverage and properties of BST films obtained using Ba(thd)2(PMDETA) as Ba source were studied.[i]

[i] J.-H. Lee, J.-Y. Kim, J. Vacuum Sci. Tech. A 17, 3033 (1999); « Metalorganic chemical vapor deposition of barium strontium titanate thin films with a more coordinatively saturated Ti precursor, Ti(dmae)4 (dmae=dimethylaminoethoxide) », doi.org/10.1116/1.582001, avs.scitation.org/doi/abs/10.1116/1.582001

Barium bis(2,2,6,6-tetramethylheptane-3,5-dionate) (N,N’,N’’,N’’’-tetrahexyltriethylentetramine adduct Ba(thd)2(THTETA)

Monomeric Barium bis(2,2,6,6-tetramethylheptane-3,5-dionate) (N,N’,N’’,N’’’-tetrahexyltriethylentetramine adduct Ba(thd)2(THTETA) has been synthesized. It is a liquid with viscosity 246 centipoise at 40°C, and is flash vaporizable with negligible residue at 240°C.

Ba(thd)2(THTETA), in combination with Ti(OCH2CH2NMe2)4, and O2 and nitrous oxide (NO?) as oxidizing agents have been applied for the growth of BaTiO3 films at substrate temperature 400-500°C [[i]]

[i][43, R.G. Gordon, S.T. Barry, R.N.R. Broomhall-Dillard, N. DiCeglie, X. Liu, D.J. Teff, Proc.-Electrochem.Soc., 1999, 98-23, 270-279]

Bis(2,2,6,6-tetramethyl-3,5-octanedionato)barium Ba(TMOD)2

Barium (II) 2,2,6,6-tetramethyl-3,5-octanedionate is, as determined by X-Ray analysis, a tetramer in solid state [[i]] and associated in the vapor phase as well [[ii]]. The structure (Fig. ) resembles a dimer of dimers.

Igumenov studied the effect of sterically hindered methoxy-β-diketonates on the volatility of Ba complexes, which induced increased thermal stability but little improvement in volatility.[[iii]]

Rees prepared several new ligands such as C5H4(CH2)nERm (n=2,3; ERm=OMe, OEt, NMe2),[[iv]] O(CH2-CH2O)nR (n=2,3; R=Me, Et),[[v]] and tBuCOCH2CO(CH2)3-OMe [[vi]] to improve the stabilities and volatilities of the CVD precursors, and synthesized some new liquid barium complexes with these ligands.

Ba(tmod)2 for Ba MOCVD

Bis(2,2,6,6-tetramethyl-3,5-octanedionato)barium Ba(TMOD)2 has been applied for the MOCVD growth of LnBa2Cu3Oy (Ln = Sm, Gd, Yb). [[vii]]

[i] (a) Gleizes, A.; Sans-Lenain, S.; Medus, D. C. R. Acad. Sci. Paris II, 1991,313, 761. (b) Drozdov, A .A,; Trojanov, S. I. Polyhedron 1992,22. 2877.

[ii]Belcher, R.; Cranley, C. P.; Majer, J . R.; Stephen, W. I.; Uden, P. C. Anal. Chim. Acta 1972, 60, 109

[iii] Igumenov, I. K.; Semyannikov, P. P.; Belaya, S. V.; Zanina, A. S.; Shergina, S. I.; Sokolov, I. E. Polyhedron 1996, 15, 4521.

[iv] Rees, Jr., W. S.; Dippel, K. A. In Chemical Processing of Advanced Materials; Hench, L. H., Ed.; Wiley: New York, 1992.

[v] Rees, Jr., W. S.; Moreno, D. A. J. Chem. Soc., Chem.Commun. 1991, 1759.

[vi] Rees, Jr., W. S.; Caballero, C. R.; Hesse, W. Angew.Chem., Int. Ed. Engl. 1992, 31, 735.

[vii] http://cat.inist.fr/?aModele=afficheN&cpsidt=930521

Ba(methd)2

Barium (methd)2

Ba(methd)2 contains a thd ligand modified at one methyl group to include a pendant ether donor ligand capping the coordination sphere of the metal ions. Ba(methd)2 is a volatile complex applied (in combination with Sr(methd)2) for the MOCVD of BaxSr1–xTiO3 at substrate temperatures of 400–500°C.[4]

Barium bis(1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionate) tetraglyme adduct [Ba(TDFND) 2](tetraglyme)

The tetraglyme adduct of barium bis(1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionate) complex has been synthesize and characterized by X-ray crystallography, 1H and 13C NMR, IR, mass spectrometry and TG–DSC analyses. It is thermally stable, volatile and non-hygroscopic. The thermal stability an volatility can be explained by “wrapping” of barium atom by tetraglyme ligand, leading to the saturation of its coordination sites. The complex is easily and cleanly vaporizing at 90 °C (10–2mmHg) from the liquid phase.

[Ba(TDFND) 2](tetraglyme) has been tested as precursor for MOCVD of BaPbO3 films, by a combined approach of MOCVD and lead vapour diffusion. (PbCO3 has used as lead source).[[i][PS1] ]

[i]Graziella Malandrino, Ignazio L. Fragalà, Deborah A. Neumayer, Charlotte L. Stern, Bruce J. Hinds and Tobin J. Marks

J. Mater. Chem., 1994,4, 1061-1066, DOI: 10.1039/JM9940401061

“Synthesis, characterization and crystal structure of a new thermally stable and volatile precursor [bis(1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionato)2–tetraglyme]barium(II) for MOCVD application”

[PS1]

Synthesis, characterization and crystal structure of a new thermally stable and volatile precursor [bis(1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionato)2–tetraglyme]barium(II) for MOCVD application

Graziella Malandrino, Ignazio L. Fragalà, Deborah A. Neumayer, Charlotte L. Stern, Bruce J. Hinds and Tobin J. Marks

J. Mater. Chem., 1994,4, 1061-1066, DOI: 10.1039/JM9940401061

The new tetraglyme adduct of barium bis(1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionate) complex has been prepared and characterized by X-ray crystallography, 1H and 13C NMR, IR, mass spectrometry and thermogravimetric–differential scanning calorimetric (TG–DSC) analyses. The complex can be easily and cleanly vaporized at 90 °C (10–2mmHg) from the liquid phase. It is thermally stable, volatile and non-hygroscopic. The thermal stability can be attributed to the saturation of coordination sites due to the tetraglyme ligand which appears wrapped around the barium centre. The adduct has been used as an MOCVD precursor for the synthesis of BaPbO3 films by a combined approach of MOCVD and lead vapour diffusion. PbCO3 has been used as lead source.

Barium bis(1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionate) anhydrous [ Ba(TDFND) 2]

Barium bis(1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionate) monohydrate [Ba(TDFND) 2](H2O)

Barium 1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluorononane-4,6-dionate hydrate Ba(TDFND)2*2H2O has been synthesized and characterised by analytical and spectroscopic means. Simultaneous thermal analysis at one atmosphere reveals that [ Ba(TDFND) 2H 2O] sublimes without any decomposition. [ Ba(TDFND) 2H 2O] is the first barium complex for which this is the case; it can be dehydrated to give anhydrous [ Ba(TDFND) 2] which is also volatile.

[ Ba(TDFND) 2*H 2O] for MOCVD of BaF2

[ Ba(TDFND) 2*H 2O] has been investigated as a precursor for the MOCVD growth of BaF 2 on silicon substrates; complete orientation in the (111) direction was observed. Changes in the film growth rate with time have been observed, they were attributed to slow reorganisation of the crystal structure of [ Ba(TDFND) 2] .[[i]]

[ Ba(TDFND) 2*H 2O] for MOCVD of YBa2Cu3O7-x

[Ba(DFHD)2H2O] , in combination with [Y(DPM)3], [Cu(DPM)2], has been applied as precursors for MOCVD growth of YBaCuO layers. The Y:Ba:Cu ratios in the layers was close to the required 1:2:3 stoichiometry. [[ii]

[i] D.G. Gilliland, M.L. Hitchman, S.C. Thompson and D.J. Cole-Hamilton

DOI: 10.1051/jp3:1992179, J. Phys. III France 2 (1992) 1381-1389

http://hal.archives-ouvertes.fr/docs/00/24/88/09/PDF/ajp-jp3v2p1381.pdf

“CVD of BaF 2 with new stable and volatile complexes of barium(II)”

[ii] Simon C. Thompson, David J. Cole-hamilton, Douglas D. Gilliland, Michael L. Hitchman, John C. Barnes

Advanced Materials for Optics and Electronics, Vol.1, Iss. 2, pages 81–97, April 1992

“Stable and volatile β-diketonate complexes of copper, calcium, strontium, barium and yttrium for use as chemical vapour deposition precursors”

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