Arne Baunemann

Deposition of microcrystalline [Cu3(btc)2] and [Zn2(bdc)2(dabco)] at alumina and silica surfaces modified with patterned self assembled organic monolayers: evidence of surface selective and oriented growth

The deposition of microcrystalline, phase pure [Cu3(btc)2] (1) and [Zn2(bdc)2(dabco)] (2) under solvothermal conditions on alumina and on silica surfaces modified with self assembled organic monolayers has been studied. The growth of 1 is remarkably surface selective and does not take place on silica but does on alumina. In contrast the growth of 2 is not surface selective at all and densely packed coatings were obtained on silica and on alumina surfaces. Most interestingly, [Cu3(btc)2] shows an oriented growth mode on both c-plane sapphire and COOH-terminated SAMs at SiO2/Si(100) wafers. The single crystals of 1 are attached to the organic surface via the (111) face, while on c-plane sapphire the crystals interact via the (100) lattice plane leading to different shapes of the crystals: pyramids on sapphire and fully developed octahedra on the COOH-SAM. The gas adsorption properties of the obtained coatings were demonstrated by reversible loading with water and with pyridine in the case of 1 and loading with [(η5-C5H5)Pd(η3-C3H5)] as a typical example of a MOCVD precursor for both 1 and 2 which allows the fabrication of Pd nanoparticle loaded MOF thin films.

Low-Temperature Atomic Layer Deposition of Copper Metal Thin Films: Self-Limiting Surface Reaction of Copper Dimethylamino-2-propoxide with Diethylzinc†

A uniform, conformal, pure copper metal thin film was grown at very low substrate temperatures (100-120 degrees C) on Si(100) substrates by atomic layer deposition involving the ligand exchange of [Cu(OCHMeCH(2)NMe(2))(2)] with Et(2)Zn (see scheme). Patterned copper thin films of Cu nanotubes (diameter 150 nm, length 12 microm) were fabricated.

Tantalum complexes with all nitrogen coordination sphere: mixed amido-, imido-, guanidinato complexes of tantalum and their thermal behaviour

Novel mixed amido-/imido-/guanidinato-complexes of tantalum are reported. The complexes were synthesised by insertion reactions of carbodiimides of the type C(NR)2(R =iso-propyl (i-Pr)) into the M-N bonds of tantalum mixed amido/imido complexes. Three representative complexes were synthesised and fully characterised by 1H-NMR, 13C-NMR, CHN-analysis and mass spectroscopy. The crystal structure of the complex [Ta(NMe2){(i-Pr-N)2C(NMe2)}2(N-t-Bu)](1)(Me = methyl, t-Bu =tert-butyl) is presented and discussed. The complexes are solids that can be quantitatively sublimed at moderate temperatures (120-130 degrees C) without any sign of decomposition. The thermal properties of the new compounds were studied (TGA) and preliminary MOCVD-experiments were performed. TaN films were deposited and characterised by XRD and XPS.

Precursor chemistry for TiO2: titanium complexes with a mixed nitrogen/oxygen ligand sphere

Novel mixed amido-malonato complexes of titanium are reported. The complexes were synthesized by partially replacing the amido groups from the complexes [Ti(NMe2)4] and [Ti(NEt2)4] via Brønstedt acid/base reactions, using the malonate-ligands di-isopropylmalonate (Hdpml) and di-tert-butylmalonate (Hdbml). Four representative complexes were synthesized and fully characterised by 1H NMR, 13C NMR, CHN analysis and mass spectrometry. The crystal structures of the six-coordinated complexes [Ti(NMe2)2(dbml)2] (3) and [Ti(NEt2)2(dbml)2] (4) are presented and discussed. The complexes are solids and the chemical and thermal characteristics of the complexes strongly depend on the substitution at the malonate ligand. While dpml containing complexes show a promising behaviour for classical MOCVD, dbml containing complexes seem to be more suitable for liquid injection-metal-organic chemical vapour deposition (LI-MOCVD). Based on its thermal characteristics, the most promising complex for thermal CVD, [Ti(NEt2)2(dpml)2] (2) was selected for preliminary MOCVD experiments, which indicate a good suitability for the deposition of TiO2 thin films.

Mononuclear precursor for MOCVD of HfO2 thin films

We report the precursor characteristics of a novel mononuclear mixed alkoxide compound [Hf(O(i)Pr)2(tbaoac)2] and its application towards MOCVD of HfO2 thin films in a production tool CVD reactor.