@inproceedings{TallaridaSchmeisserZheng, author = {Tallarida, Massimo and Schmeißer, Dieter and Zheng, Fan}, title = {X-ray Absorption and Photoemission Spectroscopy of 3C- and 4H-SiC}, language = {en} } @inproceedings{TallaridaSohalSchmeisser, author = {Tallarida, Massimo and Sohal, Rakesh and Schmeißer, Dieter}, title = {Resonant photoemission at the oxygen K edge as a tool to study the electronic properties of defects at SiO2/Si and SiO2/SiC interfaces}, language = {en} } @misc{SchroederLupinaSeifarthetal., author = {Schroeder, Thomas and Lupina, Grzegorz and Seifarth, Olaf and Tallarida, Massimo and Schmeißer, Dieter}, title = {Synchrotron radiation x-ray photoelectron spectroscopy study on the interface chemistry of high-k PrxAl2-xO3 (x=0-2) dielectrics on TiN for dynamic random access memory applications}, series = {Journal of Applied Physics}, volume = {102}, journal = {Journal of Applied Physics}, number = {1}, issn = {0021-8979}, pages = {014103}, language = {en} } @misc{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {Study of Bulk and Interface Defects in Silicon Oxide with X-ray Absorption Spectroscopy}, series = {Materials Science and Engineering : B}, volume = {144}, journal = {Materials Science and Engineering : B}, number = {1-3}, issn = {0921-5107}, pages = {23 -- 26}, language = {en} } @misc{SionckeLinBrammertzetal., author = {Sioncke, Sonja and Lin, Hang-Chu and Brammertz, Guy and Delabie, Annelies and Conard, Thierry and Franquet, Alexis and Caymax, Matty and Meuris, Marc and Schmeißer, Dieter and Tallarida, Massimo}, title = {ALD on high mobility channels: engineering the proper gate stack passivation}, series = {ECS Transactions}, volume = {33}, journal = {ECS Transactions}, number = {2}, issn = {1938-5862}, pages = {9 -- 23}, language = {en} } @misc{TammKemellKozlovaetal., author = {Tamm, Aile and Kemell, Marianna and Kozlova, Jekaterina and Sajavaara, Timo and Tallarida, Massimo and Kukli, Kaupo and Sammelselg, V. and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Atomic Layer Deposition and Characterization of Erbium Oxide-Doped Zirconium Oxid Thin Films}, series = {Journal of The Electrochemical Society}, volume = {157}, journal = {Journal of The Electrochemical Society}, number = {10}, pages = {G193 -- G201}, language = {en} } @misc{KukliAarikAidlaetal., author = {Kukli, Kaupo and Aarik, Jaan and Aidla, Aleks and Uustare, Teet and J{\~o}gi, Indrek and Lu, Jun and Tallarida, Massimo and Kemell, Marianna and Kiisler, Alma- Asta and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Structure and morphology of Ru films grown by atomic layer deposition from 1-ethyl-1´-methyl-ruthenocene}, series = {Journal of Crystal Growth}, volume = {312}, journal = {Journal of Crystal Growth}, number = {12-13}, issn = {0022-0248}, doi = {10.1016/j.jcrysgro.2010.03.033}, pages = {2025 -- 2032}, language = {en} } @misc{KolanekTallaridaKaravaevetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {In situ studies of the atomic layer deposition of thin HfO2 dielectrics by ultra high vacuum atomic force microscope}, language = {en} } @misc{SchmeisserHenkelBergholzetal., author = {Schmeißer, Dieter and Henkel, Karsten and Bergholz, Matthias and Tallarida, Massimo}, title = {The band gab and band offset in ultrathin oxide-semiconductor heterostructures}, language = {en} } @inproceedings{KolanekTallaridaKaravaevetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {In situ measurements of the atomic layer deposition of high-k dielectrics by atomic force microscope for advanced microsystems}, series = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, booktitle = {International Students and Young Scientists Workshop "Photonics and Microsystems", 2009, 25 - 27 June 2009, Harz University, Wernigerode, Germany}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-4303-1}, pages = {47 -- 51}, language = {en} } @inproceedings{TallaridaKaravaevKolaneketal., author = {Tallarida, Massimo and Karavaev, Konstantin and Kolanek, Krzysztof and Schmeißer, Dieter}, title = {Nobel "in-situ2" Approach to Modified ALD Processes for Nano-functional Metals Oxide Films}, language = {en} } @misc{SchmeisserHenkelMuelleretal., author = {Schmeißer, Dieter and Henkel, Karsten and M{\"u}ller, Klaus and Tallarida, Massimo}, title = {Interface Reactions in Ultrathin Functional Dielectric Films}, language = {en} } @misc{SchmeisserTallaridaHenkeletal., author = {Schmeißer, Dieter and Tallarida, Massimo and Henkel, Karsten and M{\"u}ller, Klaus and Mandal, Dipankar and Chumakov, Dmytro and Zschech, Ehrenfried}, title = {Characterization of oxidic and organic materials with synchrotron radiation based XPS and XAS}, language = {en} } @misc{TallaridaKaravaevSchmeisser, author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {HfO2/Si interface formation in atomic layer deposition films: an in situ investigation}, language = {en} } @article{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {Study of silicon/oxides interfaces by means of Si2p resonant photoemission}, language = {en} } @article{TallaridaKaravaevSchmeisser, author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {The initial atomic layer deposition of HfO2/Si(001) as followed in situ by synchrotron radiation photoelectron spectroscopy}, language = {en} } @article{SohalLupinaLippertetal., author = {Sohal, Rakesh and Lupina, Grzegorz and Lippert, Gunther and Wenger, Christian and Seifarth, Olaf and Schr{\"o}der, Thomas and Tallarida, Massimo and Schmeißer, Dieter}, title = {Interface chemistry of high-k PrxAl2-xO3 (x=2-0) dielectrics on TiN for dynamic random access memory applications}, language = {en} } @inproceedings{TallaridaKaravaevSchmeisseretal., author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter and Zschech, Ehrenfried}, title = {HfO2 ALD-growth studied by in situ photoemission}, series = {Proceedings of 15th Workshop on Dielectrics in Micoelectronics, Bad Saarow, 23 - 25 June 2008}, booktitle = {Proceedings of 15th Workshop on Dielectrics in Micoelectronics, Bad Saarow, 23 - 25 June 2008}, pages = {289 -- 290}, language = {en} } @misc{TallaridaAdelmannDelabieetal., author = {Tallarida, Massimo and Adelmann, Christoph and Delabie, Annelies and Elshocht, Sven van and Caymax, Matty and Schmeißer, Dieter}, title = {Surface chemistry and Fermi level movement during the self-cleaning of GaAs by trimethyl-aluminum}, series = {Applied physics letters}, volume = {99}, journal = {Applied physics letters}, number = {4}, issn = {1077-3118}, doi = {10.1063/1.3615784}, pages = {042906-1 -- 042906-3}, language = {en} } @misc{TallaridaWeisheitKolaneketal., author = {Tallarida, Massimo and Weisheit, Martin and Kolanek, Krzysztof and Michling, Marcel and Engelmann, Hans-J{\"u}rgen and Schmeißer, Dieter}, title = {Atomic layer deposition of nanolaminate oxide films on Si}, series = {Journal of Nanoparticle Research}, volume = {13}, journal = {Journal of Nanoparticle Research}, number = {11}, doi = {10.1007/s11051-011-0319-x}, pages = {5975 -- 5983}, language = {en} } @inproceedings{WyrodekTallaridaWeisheitetal., author = {Wyrodek, Jakub and Tallarida, Massimo and Weisheit, Martin and Schmeißer, Dieter}, title = {Determination of interfacial layers in high-k nanomaterials by ADXPS measurements}, language = {en} } @inproceedings{StarzykTallaridaSchmeisser, author = {Starzyk, Łukasz and Tallarida, Massimo and Schmeißer, Dieter}, title = {Band alignment of high-k/SiO2/Si stacks incorporating Zr and Al oxides prepared by atomic layer deposition}, language = {en} } @misc{KolanekTallaridaSchmeisser, author = {Kolanek, Krzysztof and Tallarida, Massimo and Schmeißer, Dieter}, title = {Atomic layer deposition of HfO2 investigated in situ by means of a noncontact atomic force microscopy}, language = {en} } @misc{KolanekTallaridaMichlingetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Michling, Marcel and Karavaev, Konstantin and Schmeißer, Dieter}, title = {Atomic layer deposition reactor for fabrication of metal oxides}, language = {en} } @misc{TallaridaKukliMichlingetal., author = {Tallarida, Massimo and Kukli, Kaupo and Michling, Marcel and Ritala, Mikko and Leskel{\"a}, Markku and Schmeißer, Dieter}, title = {Substrate Reactivity Effects in the Atomic Layer Deposition of Aluminum Oxide from Trimethylaluminum on Ruthenium}, series = {Chemistry of Materials}, volume = {23}, journal = {Chemistry of Materials}, number = {13}, issn = {0897-4756}, pages = {3159 -- 3168}, language = {en} } @misc{TallaridaFriedrichStaedteretal., author = {Tallarida, Massimo and Friedrich, Daniel and St{\"a}dter, Matthias and Michling, Marcel and Schmeißer, Dieter}, title = {Growth of TiO2 with Thermal and Plasma Enhanced Atomic Layer Deposition}, series = {Journal of Nanoscience and Nanotechnology}, volume = {11}, journal = {Journal of Nanoscience and Nanotechnology}, number = {9}, issn = {1533-4880}, pages = {8049 -- 8053}, language = {en} } @misc{TallaridaKaravaevSchmeisser, author = {Tallarida, Massimo and Karavaev, Konstantin and Schmeißer, Dieter}, title = {Novel "In-situ2" Approach to Modified ALD Processes for Nano-functional Metal Oxide Films}, language = {en} } @misc{KaravaevKolanekTallaridaetal., author = {Karavaev, Konstantin and Kolanek, Krzysztof and Tallarida, Massimo and Schmeißer, Dieter}, title = {In-Situ Studies of ALD Growth of Hafnium Oxide Films}, language = {en} } @article{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {Study of bulk and interface defects in silicon oxide with X-ray absorption spectroscopy}, language = {en} } @inproceedings{KaravaevTallaridaSchmeisser, author = {Karavaev, Konstantin and Tallarida, Massimo and Schmeißer, Dieter}, title = {In-situ Atomic Layer Deposition growth of Hafnium oxide}, series = {DEDIS-Nano-Days, October 11th and October 12th, 2007}, booktitle = {DEDIS-Nano-Days, October 11th and October 12th, 2007}, editor = {Vierhaus, Heinrich Theodor}, publisher = {BTU}, address = {Cottbus}, pages = {13 -- 19}, language = {en} } @article{TallaridaSohalSchmeisser, author = {Tallarida, Massimo and Sohal, Rakesh and Schmeißer, Dieter}, title = {Resonant photoemission at the Oxygen K edge as a tool to study the eletronic properties of defects at SiO2/Si and SiO2/SiC interfaces}, language = {en} } @misc{KolanekTallaridaMichlingetal., author = {Kolanek, Krzysztof and Tallarida, Massimo and Michling, Marcel and Schmeißer, Dieter}, title = {In situ study of the atomic layer deposition of HfO2 on Si}, series = {Journal of Vacuum Science and Technology}, journal = {Journal of Vacuum Science and Technology}, number = {A 30}, issn = {0734-2101}, pages = {01A143-1 -- 01A143-15}, language = {en} } @misc{KolanekTallaridaSchmeisser, author = {Kolanek, Krzysztof and Tallarida, Massimo and Schmeißer, Dieter}, title = {Height distribution of atomic force microscopy images as a tool for atomic layer deposition characterization}, series = {Journal of Vacuum Science and Technology : A}, volume = {31}, journal = {Journal of Vacuum Science and Technology : A}, number = {1}, doi = {10.1116/1.4754557}, pages = {01A104-1 -- 01A104-9}, abstract = {The authors propose the analysis of surface height histograms as a tool for the atomic layer deposition (ALD) growth characterization in the initial stage of the process. ALD of HfO2 on a Si(100)/SiO2 substrate was investigated in situ by ultra high vacuum atomic force microscope working in noncontact mode. The ALD cycles, made by using tetrakis-di-methyl-amido-Hf and H2O as precursors, were performed at 230 C. After each ALD cycle, the relation between the film growth and the root mean square surface roughness was studied. Parameters equivalent to HfO2 layer thickness, coverage, and surface roughness of the substrate and deposited material can be calculated in the proposed routine.}, language = {en} } @misc{KukliDimriTammetal., author = {Kukli, Kaupo and Dimri, Mukesh Chandra and Tamm, Aile and Kemell, Marianna and K{\"a}{\"a}mbre, Tanel and Vehkam{\"a}ki, Marko and Puttaswamy, Manjunath and Stern, Raivo and Kuusik, Ivar and Kikas, Arvo and Tallarida, Massimo and Schmeißer, Dieter and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Structural and Magnetic Studies on Iron Oxide and Iron-Magnesium Oxide Thin Films Deposited Using Ferrocene and (Dimethylaminomethyl)ferrocene Precursors}, series = {ECS Journal of Solid State Science and Technology}, volume = {2}, journal = {ECS Journal of Solid State Science and Technology}, number = {3}, issn = {2162-8769}, doi = {10.1149/2.004303jss}, pages = {N45 -- N54}, abstract = {Iron oxide and magnesium-doped iron oxide films were grown by atomic layer deposition in the temperature range of 350-500 ◦C from ferrocene, (dimethylaminomethyl)ferrocene, magnesiumβ-diketonate, and ozone. Phase composition of the films depended on the deposition temperature, as magnetite and/or maghemite tended to form instead of hematite upon lowering the temperature. Iron oxide layers were also mixed with magnesium oxide by alternate deposition of MgO and Fe2O3 which also favored the formation of magnetite or maghemite structure prior to hematite. Scanning electron microscopy implied the smoothening of the films after doping with magnesium oxide. Magnetometry was used to study the effects of temperature and doping levels on the magnetic properties of the films.}, language = {en} } @misc{PopoviciDelabieAdelmannetal., author = {Popovici, Mihaela and Delabie, Annelies and Adelmann, Christoph and Meersschaut, Johan and Franquet, Alexis and Tallarida, Massimo and Berg, Jaap van den and Richard, Olivier and Swerts, Johan and Tomida, Kazuyuki and Kim, Min-Soo and Tielens, Hilde and Bender, Hugo and Conard, Thierry and Jurczak, Malgorzata and Elshocht, Sven van and Schmeißer, Dieter}, title = {Understanding the Interface Reactions of Rutile TiO2 Grown by Atomic Layer Deposition on Oxidized Ruthenium}, series = {ECS Journal of Solid State Science and Technology}, volume = {2}, journal = {ECS Journal of Solid State Science and Technology}, number = {1}, issn = {2162-8769}, doi = {10.1149/2.035301jss}, pages = {N23 -- N27}, abstract = {The atomic layer deposition of titanium oxide TiO2 on ruthenium and oxidized ruthenium with titanium methoxide as metal precursor and H2O and O3 as oxidant was investigated by Rutherford backscattering (RBS) and time of flight secondary ion mass spectrometry (TOFSIMS). An ultra-thin layer of TiO2 deposited a priori with H2O plays the role of protection of Ru(Ox) substrates against etching by O3. Information about thin films (∼3 nm) interfacial reactions, thickness and structure was brought by Medium Energy Ion Scattering Spectroscopy (MEIS) and X-ray absorption spectroscopy (XAS) measurements. The growth enhancements observed in the first stages of the deposition depends on the pre-treatment (pre-oxidation, H2O based interlayer thickness) of the Ru substrate. Thick films (∼14 nm) were analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The as deposited TiO2 films are crystalline with rutile structure, as resulted from structural analyzes. However, the presence of small amounts of anatase was detected by soft X-ray absorption spectroscopy (XAS) and is strongly influenced by the surface pre-treatment of the Ru substrate. The electrical properties (equivalent oxide thickness and leakage current density) correlate with a different rutile/anatase ratio present in the films.}, language = {en} } @misc{TallaridaSchmeisser, author = {Tallarida, Massimo and Schmeißer, Dieter}, title = {In situALD experiments with synchrotron radiation photoelectron spectroscopy}, series = {Semiconductor Science and Technology}, volume = {27}, journal = {Semiconductor Science and Technology}, number = {7}, issn = {1361-6641}, doi = {10.1088/0268-1242/27/7/074010}, pages = {074010}, abstract = {In this contribution, we describe some features of atomic layer deposition (ALD) investigated by means of synchrotron radiation photoelemission spectroscopy (SR-PES). In particular, we show how the surface sensitivity of SR-PES combined with the in situ nature of our investigations can point out interactions between the substrate and ALD precursors. We observed changes on all substrates investigated, included Si, GaAs, Ru and their surface oxides. These interactions are extremely important during the first ALD cycles and induce modifications in the substrate, which might lead to its functionality enhancement.}, language = {en} } @misc{TallaridaAdelmannDelabieetal., author = {Tallarida, Massimo and Adelmann, Christoph and Delabie, Annelies and van Elshocht, Sven and Caymax, Matty and Schmeißer, Dieter}, title = {GaAs clean up studied with synchrotron radiation photoemission}, series = {IOP Conference Series : Materials Science and Engineering}, journal = {IOP Conference Series : Materials Science and Engineering}, number = {41}, issn = {1757-899X}, doi = {10.1088/1757-899X/41/1/012003}, pages = {012003}, abstract = {In this contribution we describe the chemical changes at the surface of GaAs upon adsorption of tri-methyl-aluminum (TMA). TMA is used to grow Al2O3 with atomic layer deposition (ALD) usually using H2O as oxygen source. Recently, it was pointed out that the adsorption of TMA on various III-V surfaces reduces the native oxide, allowing the growth of an abrupt III-V/High-K interface with reduced density of defects. Synchrotron radiation photoemission spectroscopy (SR-PES) is a powerful method to characterize surfaces and interfaces of many materials, as it is capable todetermine their chemical composition as well as the electronic properties. We performed in-situ SR-PES measurements after exposing a GaAs surface to TMA pulses at about 250°C. Upon using the possibility of tuning the incident photon energy we compared the Ga3d spectra at 41 eV, 71 eV, 91 eV and 121 eV, as well as the As3d at 71 eV and 91 eV. Finally, we show that using SR-PES allows a further understanding of the surface composition, which is usually not accessible with other techniques.}, language = {en} } @inproceedings{SchmeisserRichterTallarida, author = {Schmeißer, Dieter and Richter, Matthias and Tallarida, Massimo}, title = {Intrinsic defects in TiO2 to explain resistive switching devices}, series = {Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany}, booktitle = {Frontiers in Electronic Materials: A Collection of Extended Abstracts of the Nature Conference Frontiers in Electronic Materials, June 17 to 20 2012, Aachen, Germany}, editor = {Heber, J{\"o}rg and Schlom, Darrell and Tokura, Yoshinori and Waser, Rainer and Wuttig, Matthias}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-41191-7}, doi = {10.1002/9783527667703.ch45}, pages = {255 -- 256}, language = {en} } @misc{KukliKemellPuukilainenetal., author = {Kukli, Kaupo and Kemell, Marianna and Puukilainen, Esa and Aarik, Jaan and Aidla, Aleks and Sajavaara, Timo and Laitinen, Mikko and Tallarida, Massimo and Sundqvist, Jonas and Ritala, Mikko and Leskel{\"a}, Markku}, title = {Atomic Layer Deposition of Ruthenium Films from (Ethylcyclopentadienyl)(pyrrolyl)ruthenium and Oxygen}, series = {Journal of the Electrochemical Society}, volume = {158}, journal = {Journal of the Electrochemical Society}, number = {3}, issn = {0013-4651}, doi = {10.1149/1.3533387}, pages = {D158 -- D165}, abstract = {Ru films were grown by atomic layer deposition in the temperature range of 275-350 degrees C using (ethylcyclopentadienyl)(pyrrolyl)ruthenium and air or oxygen as precursors on HF-etched Si, SiO(2), ZrO(2), and TiN substrates. Conformal growth was examined on three-dimensional silicon substrates with 20: 1 aspect ratio. ZrO(2) promoted the nucleation of Ru most efficiently compared to other substrates, but the films roughened quickly on ZrO(2) with increasing film thickness. The minimum number of cycles required to form continuous and conductive metal layers could be decreased by increasing the length of the oxygen pulse. In order to obtain well-conducting Ru films growth to thicknesses of at least 8-10 nm on any surface was necessary. Resistivities in the ranges of 30-60 and 14-16 mu Omega . cm were achieved for 4-6 and 10-15 nm thick films, respectively. Delamination became an issue in the Ru films grown to thicknesses about 10 nm and higher.}, language = {en} } @inproceedings{Tallarida, author = {Tallarida, Massimo}, title = {III-V/oxide interfaces investigated with synchrotron radiation photoemission spectroscopy}, series = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, booktitle = {Meeting Abstracts-Electrochemical Society, Pacific Rim Meeting on Electrochemical and Solid-State Science, Honolulu, 2012}, publisher = {The Electrochemical Society}, pages = {2587 -- 2587}, language = {en} } @misc{TallaridaAdelmannDelabieetal., author = {Tallarida, Massimo and Adelmann, Christoph and Delabie, Annelies and Elshocht, Sven van and Caymax, Matty and Schmeißer, Dieter}, title = {III-V/Oxide Interfaces Investigated with Synchrotron Radiation Photoemission Spectroscopy}, series = {ECS Transactions}, volume = {50}, journal = {ECS Transactions}, number = {4}, issn = {1938-6737}, doi = {10.1149/05004.0123ecst}, pages = {123 -- 128}, abstract = {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.}, language = {en} } @misc{BarrecaCarraroGasparottoetal., author = {Barreca, Davide and Carraro, Giorgio and Gasparotto, Alberto and Maccato, Chiara and Rossi, Francesca and Salviati, Giancarlo and Tallarida, Massimo and Das, Chittaranjan and Fresno, Fernando and Korte, Dorota and Štangar, Urška Lavrenčič and Franko, Mladen and Schmeißer, Dieter}, title = {Surface Functionalization of Nanostructured Fe2O3 Polymorphs: From Design to Light-Activated Applications}, series = {ACS Applied Materials \& Interfaces}, volume = {5}, journal = {ACS Applied Materials \& Interfaces}, number = {15}, issn = {1944-8252}, doi = {10.1021/am401475g}, pages = {7130 -- 7138}, abstract = {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.}, language = {en} } @misc{AdelmannCuypersTallaridaetal., author = {Adelmann, Christoph and Cuypers, Daniel and Tallarida, Massimo and Rodriguez, Leonard and De Clercq, Astrid and Friedrich, Daniel and Conard, Thierry and Delabie, Annelies and Seo, Jin Won and Locquet, Jean-Pierre and De Gendt, Stefan and Schmeißer, Dieter and Elshocht, Sven van and Caymax, Matty}, title = {Surface Chemistry and Interface Formation during the Atomic Layer Deposition of Alumina from Trimethylaluminum and Water on Indium Phosphide}, series = {Chemistry of Materials}, volume = {25}, journal = {Chemistry of Materials}, number = {7}, issn = {1520-5002}, doi = {10.1021/cm304070h}, pages = {1078 -- 1091}, abstract = {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.}, language = {en} } @misc{RossiFabbriTallaridaetal., author = {Rossi, Francesca and Fabbri, Filippo and Tallarida, Massimo and Schmeißer, Dieter and Modreanu, Mircea and Attolini, Giovanni and Salviati, Giancarlo}, title = {Structural and luminescence properties of HfO2 nanocrystals grown by atomic layer deposition on SiC/SiO2 core/shell nanowires}, series = {Scripta Materialia}, volume = {69}, journal = {Scripta Materialia}, number = {10}, issn = {1359-6462}, doi = {10.1016/j.scriptamat.2013.08.017}, pages = {744 -- 747}, abstract = {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.}, language = {en} } @misc{HaeberleHenkelGargourietal., author = {Haeberle, J{\"o}rg and Henkel, Karsten and Gargouri, Hassan and Naumann, Franziska and Gruska, Bernd and Arens, Michael and Tallarida, Massimo and Schmeißer, Dieter}, title = {Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al2O3-films}, series = {Beilstein Journal of Nanotechnology}, volume = {2013}, journal = {Beilstein Journal of Nanotechnology}, number = {4}, issn = {2190-4286}, doi = {10.3762/bjnano.4.83}, pages = {732 -- 742}, abstract = {We report on results on the preparation of thin (<100 nm) aluminum oxide (Al2O3) films on silicon substrates using thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition (PE-ALD) in the SENTECH SI ALD LL system. The T-ALD Al2O3layers were deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt) and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate) over 4" wafers and correlatethem to X-ray photoelectron spectroscopy (XPS) results. The 200°C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is not influenced significantly. Initial state energy shifts in all PE-ALD samples are observed which we attribute to a net negative charge within the films.}, language = {en} } @inproceedings{CuypersDorpTallaridaetal., author = {Cuypers, Daniel and Dorp, Dennis H. von and Tallarida, Massimo and Brizzi, Simone and Rodriguez, Leonard and Conard, Thierry and Arnauts, Sophia and Schmeißer, Dieter and Adelmann, Christoph and De Gendt, Stefan}, title = {Study of InP Surfaces After Wet Chemical Treatments}, series = {Meeting Abstracts-Electrochemical Society, San Francisco, 2013}, booktitle = {Meeting Abstracts-Electrochemical Society, San Francisco, 2013}, publisher = {The Electrochemical Society}, pages = {S. 2132}, language = {en} } @misc{CuypersDorpTallaridaetal., author = {Cuypers, Daniel and Dorp, Dennis H. von and Tallarida, Massimo and Brizzi, Simone and Rodriguez, Leonard and Conard, Thierry and Arnauts, Sophia and Schmeißer, Dieter and Adelmann, Christoph and De Gendt, Stefan}, title = {Study of InP Surfaces after Wet Chemical Treatments}, series = {ECS Transactions}, volume = {58}, journal = {ECS Transactions}, number = {6}, issn = {1938-6737}, doi = {10.1149/05806.0297ecst}, pages = {297 -- 303}, abstract = {In this work synchrotron radiation photoemission spectroscopy (SRPES) is used to study InP surfaces after different wet chemical treatments. All results are compared to a typical fingerprint of surface components present on an as received InP sample. It is shown that acidified (HCl and H₂SO₄) treatments efficiently remove the native phosphate, although components like Pᴼ, Inᴼ and P(2±∆)+ remain present. In alkaline solution (NH₄OH) oxide remains present at the surface. As an alternative treatment, the immersion into (NH₄)₂S was studied. This passivation treatment results in fewer surface components which suggests that a higher quality surface is obtained.}, language = {en} } @misc{CuypersDorpTallaridaetal., author = {Cuypers, Daniel and Dorp, Dennis H. von and Tallarida, Massimo and Brizzi, Simone and Conard, Thierry and Rodriguez, Leonard and Mees, M. and Arnauts, Sophia and Schmeißer, Dieter and Adelmann, Christoph and De Gendt, Stefan}, title = {Study of InP Surfaces after Wet Chemical Treatments}, series = {ECS Journal of Solid State Science and Technology}, volume = {3}, journal = {ECS Journal of Solid State Science and Technology}, number = {1}, issn = {2162-8777}, doi = {10.1149/2.005401jss}, pages = {N3016 -- N3022}, abstract = {The influence of different wet chemical treatments (HCl, H₂SO₄, NH₄OH) on the composition of InP surfaces is studied by using synchrotron radiation photoemission spectroscopy (SRPES). It is shown that a significant amount of oxide remains present after immersion in a NH₄OH solution which is ascribed to the insolubility of In³⁺ at higher pH values. Acidic treatments efficiently remove the native oxide, although components like Pᴼ, Inᴼ and P(2±Δ)+ suboxides are observed. Alternatively, the influence of a passivation step in (NH₄)₂S solution on the surface composition was investigated. The InP surface after immersion into (NH₄)₂S results in fewer surface components, without detection of Pᴼ and P(2±Δ)+ suboxides. Finally, slight etching of InP surfaces in HCl/H₂O₂ solution followed by a native oxide removal step, showed no significant effect on the surface composition.}, language = {en} } @misc{DasTallaridaSchmeisser, author = {Das, Chittaranjan and Tallarida, Massimo and Schmeißer, Dieter}, title = {Linear dichroism in ALD layers of TiO₂}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2836-7}, pages = {3785 -- 3795}, abstract = {We prepare TiO₂film by ALD and study their electronic properties by soft X-ray absorption spectroscopy (XAS) and photoelectron spectroscopy. We focus on XAS and X-ray linear dichroism to indentify band onset and learn about local distortion of the Ti-O octahedral atomic and about defects which cause Ti-based electronic states within the band gap.}, language = {en} } @misc{HenkelGargouriGruskaetal., author = {Henkel, Karsten and Gargouri, Hassan and Gruska, Bernd and Arens, Michael and Tallarida, Massimo and Schmeißer, Dieter}, title = {Capacitance and conductance versus voltage characterization of Al2O3 layers prepared by PE-ALD at 25°C ≤ T ≤ 200°C}, series = {Journal of Vacuum Science and Technology A}, volume = {1}, journal = {Journal of Vacuum Science and Technology A}, number = {32}, doi = {10.1116/1.4831897}, pages = {01A107-1 -- 01A107-10}, abstract = {In this work, plasma enhanced atomic layer deposited (PE-ALD) samples were prepared at substrate temperatures in the range between room temperature (RT) and 200 °C and investigated by capacitance-voltage and conductance-voltage recordings. The measurements are compared to standard thermal atomic layer deposition (T-ALD) at 200 °C. Very low interface state density (D it) ~1011 eV-1 cm-2 could be achieved for the PE-ALD process at 200 °C substrate temperature after postdeposition anneal (PDA) in forming gas at 450 °C. The PDA works very effectively for both the PE-ALD and T-ALD at 200 °C substrate temperature delivering also similar values of negative fixed charge density (N fix) around -2.5 × 1012 cm-2. At the substrate temperature of 150 °C, highest N fix (-2.9 × 1012 cm-2) and moderate D it (2.7 × 1011 eV-1 cm-2) values were observed. The as deposited PE-ALD layer at RT shows both low D it in the range of (1 to 3) × 1011 eV-1 cm-2 and low N fix (-4.4 × 1011 cm-2) at the same time. The dependencies of N fix, D it, and relative permittivity on the substrate temperatures and its adjustability are discussed.}, language = {en} } @misc{TallaridaDasSchmeisser, author = {Tallarida, Massimo and Das, Chittaranjan and Schmeißer, Dieter}, title = {Quantum size effects in TiO2 thin films grown by atomic layer deposition}, series = {Beilstein Journal of Nanotechnology}, journal = {Beilstein Journal of Nanotechnology}, number = {5}, issn = {2190-4286}, doi = {10.3762/bjnano.5.7}, pages = {77 -- 82}, abstract = {We study the atomic layer deposition of TiO2 by means of X-ray absorption spectroscopy. The Ti precursor, titanium isopropoxide, was used in combination with H2O on Si/SiO2 substrates that were heated at 200 °C. The low growth rate (0.15 {\AA}/cycle) and the in situ characterization permitted to follow changes in the electronic structure of TiO2 in the sub-nanometer range, which are influenced by quantum size effects. The modified electronic properties may play an important role in charge carrier transport and separation, and increase the efficiency of energy conversion systems.}, language = {en} }