TY - CHAP A1 - Tallarida, Massimo T1 - III-V/oxide interfaces investigated with synchrotron radiation photoemission spectroscopy T2 - Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012 KW - interfaces KW - III/V KW - Synchrotron Photoemission Spectroscopy Y1 - 2012 UR - http://ma.ecsdl.org/content/MA2012-02/31/2587.full.pdf+html N1 - MA2012-02(31) SP - 2587 EP - 2587 PB - The Electrochemical Society ER - TY - GEN A1 - Tallarida, Massimo A1 - Adelmann, Christoph A1 - Delabie, Annelies A1 - Elshocht, Sven van A1 - Caymax, Matty A1 - Schmeißer, Dieter T1 - III-V/Oxide Interfaces Investigated with Synchrotron Radiation Photoemission Spectroscopy T2 - ECS Transactions N2 - We used synchrotron radiation photoemission spectroscopy (SR-PES) to investigate the surface of GaAs and other III-V semiconductors after tri-methyl-aluminum (TMA) pulses performed at 250{degree sign}C. We observed the removal of native oxide and the growth of Al-oxide upon measuring the As3d, Ga3d, Al2p and VB spectra. After seven TMA pulses we performed one water pulse. As3d and Ga3d peaks showed almost no lineshape change, but a decrease of intensity due to the water adsorption. The valence band shows a change in the secondary electron cut-off and the decrease of work function. We conclude that water mostly adsorbs molecularly and induces the work function decrease. The molecular absorption of water indicates that the seven TMA pulses produce a passivated surface only partially terminated with OH groups. KW - Interfaces KW - III/V KW - Synchrotron Photoemission Spectroscopy Y1 - 2013 U6 - https://doi.org/10.1149/05004.0123ecst SN - 1938-6737 VL - 50 IS - 4 SP - 123 EP - 128 ER - TY - GEN A1 - Müller, Klaus A1 - Fleige, Michael A1 - Rachow, Fabian A1 - Schmeißer, Dieter T1 - Sabatier based CO2-methanation of flue gas emitted by conventional power plants T2 - Energy Procedia N2 - The hydrogenation CO2+ 4H2 ->CH4 + 2H2O discovered by Paul Sabatier nowadays is discussed as "Power-to-approach" to utilize excess energy from renewable electricity generation. In a laboratory scale, we investigate the Sabatier process in a simulated flue gas atmosphere of conventional base load power plants. The reaction is investigated with regard to conversion rates, yield, selectivity and long-term stability. Using a catalyst based on nickel,we extract selectivities near 100% with a conversion around 85%. Beside the influence of oxygen, we investigate further typical contaminations like NO2 and SO2. KW - Power to gas KW - CO2 -Methanation KW - Sabatier-reaction KW - flue gas Y1 - 2013 U6 - https://doi.org/10.1016/j.egypro.2013.08.028 SN - 1876-6102 VL - 40 SP - 240 EP - 248 ER - TY - CHAP A1 - Mai, Andreas A1 - Dauderstädt, Ulrike A1 - Pahner, D. A1 - Krellmann, M. A1 - Schmeißer, Dieter A1 - Wagner, M. T1 - In situ determination of laser induced degradation of micro-mirror arrays T2 - International Students and Young Scientists Workshop Photonics and Microsystems, Cottbus, Germany, 8 - 10 June 2011 N2 - The Fraunhofer Institute for Photonic Microsystems (Fraunhofer IPMS) develops spatial light modulators (SLMs) based on arrays of tiltable micro mirrors on a semiconductor chip. Typical applications are pattern generation for deepUV-laser mask writing or structured illumination in microscopy. Development and optimization of such SLMs requires detailed knowledge of the device behaviour under operating conditions. Here, the flatness of each single mirror effects the image resolution and contrast of the generated pattern and is amongst others a characteristic property of SLMs. In this context a surface topography measurement under laser exposure (in situ) was designed. The interferometric setup uses the phase-shift principle and allows a resolution in z-direction in the single-digit nanometer range. During irradiation with UV-laser light at 248 nm (KrF) and energy densities of up to 20 mJ/cm2 the change in single micro-mirrors topography was detected in situ. Measurementswith varying pulse energies were carried out to identify an impacton the device performance. In general, the setup is neither limited to a specific illumination wavelength nor to micro-mirrors as structures under test. KW - micro-mirror arrays KW - laser induced degradation Y1 - 2011 SN - 978-1-4577-1651-5 U6 - https://doi.org/10.1109/STYSW.2011.6155850 SP - 84 EP - 88 PB - IEEE CY - Piscataway, NJ ER - TY - GEN A1 - Barreca, Davide A1 - Carraro, Giorgio A1 - Gasparotto, Alberto A1 - Maccato, Chiara A1 - Rossi, Francesca A1 - Salviati, Giancarlo A1 - Tallarida, Massimo A1 - Das, Chittaranjan A1 - Fresno, Fernando A1 - Korte, Dorota A1 - Štangar, Urška Lavrenčič A1 - Franko, Mladen A1 - Schmeißer, Dieter T1 - Surface Functionalization of Nanostructured Fe2O3 Polymorphs: From Design to Light-Activated Applications T2 - ACS Applied Materials & Interfaces N2 - Nanostructured iron(III) oxide deposits are grown by chemical vapor deposition (CVD) at 400−500 °C on Si(100) substrates from Fe(hfa)2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N′N′-tetramethylethylenediamine), yielding the selective formation of α-Fe2O3or the scarcely studiedε-Fe2O3 polymorphs under suitably optimized preparative conditions. By using Ti(OPr i)4(OPri= iso-propoxy) and water asatomic layer deposition (ALD) precursors, we subsequently functionalized the obtained materials at moderate temperatures (<300°C) by an ultrathin titanomagnetite (Fe3−xTixO4) overlayer. An extensive multitechnique character-ization, aimed at elucidating the system structure, morphology, composition and optical properties, evidenced that the photoactivated hydrophilic and photocatalytic behavior of the synthesized materials is dependent both on iron oxide phase composition and ALD surface modification. The proposed CVD/ALD hybrid synthetic approach candidates itself as a powerful tool for a variety of applications where semiconductor-based nanoarchitectures can benefit from the coupling with an ad hoc surface layer. KW - chemical vapor deposition KW - atomic layer deposition KW - iron oxide KW - titanomagnetite KW - photoactivated properties Y1 - 2013 U6 - https://doi.org/10.1021/am401475g SN - 1944-8252 VL - 5 IS - 15 SP - 7130 EP - 7138 ER - TY - GEN A1 - Adelmann, Christoph A1 - Cuypers, Daniel A1 - Tallarida, Massimo A1 - Rodriguez, Leonard A1 - De Clercq, Astrid A1 - Friedrich, Daniel A1 - Conard, Thierry A1 - Delabie, Annelies A1 - Seo, Jin Won A1 - Locquet, Jean-Pierre A1 - De Gendt, Stefan A1 - Schmeißer, Dieter A1 - Elshocht, Sven van A1 - Caymax, Matty T1 - Surface Chemistry and Interface Formation during the Atomic Layer Deposition of Alumina from Trimethylaluminum and Water on Indium Phosphide T2 - Chemistry of Materials N2 - The surface chemistry and the interface formation during the initial stages of the atomic layer deposition (ALD) of Al2O3 from trimethylaluminum (TMA) and H2O on InP(100)were studied by synchrotron radiation photoemission spectroscopy and scanning tunneling microscopy. The effect of the ex situ surface cleaning by either H2SO4 or (NH4)2S was examined. It is shown that the native oxide on the InP surface consisted mainly of indium hydrogen phosphates with a P enrichment at the interface with InP. After a (NH4)2S treatment, S was present on the surface as a sulfide in both surface and subsurface sites. Exposure to TMA led to the formation of a thin AlPO4 layer, irrespective of the surface cleaning. The surface Fermi level of p-type InP was found to be pinned close to midgap after H2SO4 cleaning and moved only slightly further toward the conduction band edge upon TMA exposure, indicating that the AlPO4/InP interface was rather defective. (NH4)2S passivation led to a Fermi level position of p-type InP close to the conduction band edge. Hence, the InP surface was weakly inverted, which can be attributed to surface doping by S donors. TMA exposure was found to remove surface S, which was accompanied by a shift of the Fermi level to midgap, consistent with the removal of (part of) the S donors in combination with a defective AlPO4/InP interface. Further TMA/H2O ALD did not lead to any detectable changes of the AlPO4/InP interface and suggested simple overgrowth with Al2O3. Y1 - 2013 U6 - https://doi.org/10.1021/cm304070h SN - 1520-5002 VL - 25 IS - 7 SP - 1078 EP - 1091 ER - TY - GEN A1 - Rossi, Francesca A1 - Fabbri, Filippo A1 - Tallarida, Massimo A1 - Schmeißer, Dieter A1 - Modreanu, Mircea A1 - Attolini, Giovanni A1 - Salviati, Giancarlo T1 - Structural and luminescence properties of HfO2 nanocrystals grown by atomic layer deposition on SiC/SiO2 core/shell nanowires T2 - Scripta Materialia N2 - In this work we report the morphological, structural and luminescence properties of HfO2 nanocrystals grown on the surface of SiC/SiO2 core/shell nanowires by atomic layer deposition. All the studies are carried out in comparison with HfO2 nanocrystal aggregates grown on planar oxidized silicon substrates. The structural analyses reveal that HfO2has monoclinic structure with dif-ferent orientations. The cathodoluminescence emission shows the main components at 2.7 and 2.3 eV, deeply influenced by the arrangement and aggregation of the nanocrystals. KW - Silicon carbide KW - Silicon dioxide KW - Nanowires KW - Hafnium oxide KW - Nanocrystals Y1 - 2013 U6 - https://doi.org/10.1016/j.scriptamat.2013.08.017 SN - 1359-6462 VL - 69 IS - 10 SP - 744 EP - 747 ER - TY - THES A1 - Klocek, Jolanta T1 - Processing and investigation of thin films with incorporated carbon species for possible application as low-k materials N2 - In this thesis the detailed investigations concerning processing and stability of thin films including carbon species and their possible application as materials of a low dielectric constant (low k) are presented. In order to gather a complex information regarding the chemical, morphological and dielectric properties of the produced layer a combination of the spectroscopy: X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS) and Fourier transform infrared spectroscopy (FTIR), microscopy: atomic force microscopy (AFM) and electrical characterization: capacitance-voltage technique (CV) have been applied. The films deposited by means of variety of techniques have been described, ranging from evaporation, through spraying and dropping to spin-coating. Regarding the possible low-k application, a considerable attention has been paid to the hybrid organic-inorganic 3-aminopropyl-trimethoxysilane (APTMS) based composite materials enriched with carbon species coming from the following dopants: C60 fullerenes, [6,6]-phenyl-C61-butyric acid (PCBM), copper phthalocyanine (CuPc), and tris(dimethylvinylsilyloxy)-POSS (POSS). In the following thesis progressive steps leading to gradual decreasing of the resulting permittivity of the hybrid material is presented. As revealed by the performed investigations, the replacement of C60 within the APTMS based matrix by its better soluble derivative PCBM allows the increase of the concentration of the carbon species within the composite films. The introduction of POSS as an additional dopant gave the opportunity of increasing the resistance of the produced material against the ambient influence. With the excess of the POSS concentration an original fractal-shaped cluster formation has been observed. Finally, the dispersion of the properly chosen low concentration of CuPc and POSS molecules within the APTMS based matrix led to the fabrication of homogenous layer with an ultra-low dielectric constant of 1.8. KW - X-ray photoelectron spectroscopy KW - Capacitance–voltage characterization KW - 3-Aminopropyltrimethoxysilane KW - Low-k materials KW - Atomic force microscopy Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus-24358 UR - http://opus.kobv.de/btu/volltexte/2012/2435/ N1 - Auch im Südwestdeutschen Verlag für Hochschulschriften in Saarbrücken erschienen ER - TY - THES A1 - Kraatz, Matthias T1 - Studying the effect of Cu microstructure on electromigration reliability using statistical simulation KW - Electromigration KW - Simulation KW - Grain growth KW - Statistics Y1 - 2011 N1 - Dissertation wurde an der University of Texas in Austin eingereicht, Teilaspekte wurden an der BTU bearbeitet ER - TY - THES A1 - Karavaev, Konstantin T1 - In-situ Atomic Layer Deposition growth of Hf-oxide N2 - We have grown HfO2 on Si(001) by atomic layer deposition (ALD) using HfCl4, TEMAHf, TDMAHf and H2O as precursors. The early stages of the ALD were investigated with high-resolution photoelectron spectroscopy and x-ray absorption spectroscopy. We observed the changes occurring in the Si2p, O1s, Hf4f, Hf4d, and Cl2p (for HfCl4 experiment) core level lines after each ALD cycle up to the complete formation of two layers of HfO2. The investigation was carried out in-situ giving the possibility to determine the properties of the grown film after every ALD cycle or even after a half cycle. This work focused on the advantages of the in-situ approach in comparison to ex-situ experiments. The study provides to follow the evolution of the important properties of HfO2: contamination level, density and stoichiometry, and influence of the experimental parameters to the interface layer formation during ALD. Our investigation shows that the in-situ XPS approach for ALD gives much more information than ex-situ experiments. KW - Atomic layer deposition KW - ALD KW - X-ray photoelectron spectroscopy KW - XPS KW - Hf=2 Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus-22617 UR - http://opus.kobv.de/btu/volltexte/2011/2261/ ER -