@inproceedings{DudekLupinaKozłowskietal., author = {Dudek, Peter and Lupina, Grzegorz and Kozłowski, Grzegorz and Dabrowski, Jarek Marek and Lippert, Gunther and M{\"u}ssig, Hans-Joachim and Schmeißer, Dieter and Schroeder, Thomas}, title = {Band structure and electrical properties of MBE grown HfO2 - based alkaline earth perovskites}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 45}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 232}, abstract = {Ultra thin dielectric films (<20 nm) deposited on TiN electrodes are interesting for MIM capacitor application. High capacitance density and dielectric permittivity must be accompanied by extremely low leakage currents (10-8 A/cm2) at bias 0.5 V. To achieve such low leakage currents, high band gap and proper band alignment is required. Occupied electronic states can be probed with standard laboratory photoemission methods. Probing of unoccupied states is more challenging. Synchrotron based PES in combination with XAS forms a powerful method to study the band alignment. ASAM end station located at the U 49/2 PGM 2 beamline of BESSY II (Berlin) offers excellent conditions for performing such measurements. We investigated HfO2 - based alkaline earth perovskite - BaHfO3 with subsequent admixture of TiO2, resulting in formation of BaHf0.5Ti0.5O3 compound. The analysis of data indicates that band gap for HfO2 is similar to BaHfO3 and amounts 5.8 eV; for BaHf0.5Ti0.5O3 it decreases to 3.8 eV. We conclude that the addition of TiO2 to BaHfO3 increases significantly the dielectric permittivity but also impacts the band gap alignment. The conduction band offset shrinks, influencing the leakage current behavior.}, language = {en} } @misc{LupinaDabrowskiFormaneketal., author = {Lupina, Grzegorz and Dabrowski, Jarek Marek and Formanek, Peter and Schmeißer, Dieter and Sorge, Roland and Wenger, Christian and Zaumseil, Peter and M{\"u}ssig, Hans-Joachim}, title = {Solid-state reaction between Pr and SiO2 studied by photoelectron spectroscopy and ab initio calculations}, series = {Materials Science in Semiconductor Processing}, volume = {7}, journal = {Materials Science in Semiconductor Processing}, number = {4-6}, issn = {1369-8001}, pages = {215 -- 220}, abstract = {We report on the structural and electrical properties of Pr-based high-k dielectric films fabricated by solid-state reaction between metallic Pr and SiO2 underlayers. A non-destructive depth profiling using synchrotron radiation excited photoelectron spectroscopy (SR-PES), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were employed to examine the chemical composition and microstructure. Ab initio calculations were done to gain insight into the physical processes involved. SR-PES results indicate that Pr deposition at room temperature (RT) leads to the formation of a Pr silicide and a Pr oxide, what is in good agreement with the scenario expected from ab initio calculations. As revealed by TEM and electrical measurements, oxidation of the reacted structures, followed by annealing, results in a stacked dielectric composed of a SiO2-based buffer with an enhanced permittivity and a Pr silicate film with a high dielectric constant. The leakage current density of 10-4 A/cm2 was measured for stacks with capacitance equivalent thickness (CET) of 1.5 nm prepared by evaporation of the Pr layer on a 1.8 nm SiO2 film, followed by oxidation in air ambient and annealing in N2 atmosphere. The capacitance-voltage (C-V) curves exhibit a large flatband voltage (VFB) shift indicating the presence of a positive charge in the stack. Switching away from the Al contacts to Au gate electrodes introduces a significant reduction of the VFB by 1.3 eV, what is much more than the change expected from the work function difference between Al and Au (not, vert, similar0.9 eV). This in turn implies that VFB is strongly affected by the gate interface electrode.}, language = {en} } @misc{MuessigDabrowskiWengeretal., author = {M{\"u}ssig, Hans-Joachim and Dabrowski, Jarek Marek and Wenger, Christian and Lupina, Grzegorz and Sorge, Roland and Formanek, Peter and Zaumseil, Peter and Schmeißer, Dieter}, title = {Ultrathin Dielectric Films Grown by Solid Phase Reaction of Pr with SiO2}, series = {MRS Proceedings}, volume = {811}, journal = {MRS Proceedings}, issn = {1946-4274}, pages = {D7.10.}, language = {en} } @incollection{SchmeisserLupinaMuessig, author = {Schmeißer, Dieter and Lupina, Grzegorz and M{\"u}ssig, Hans-Joachim}, title = {High reactivity of Pr on oxide covered 4H-SiC}, series = {Bessy annual report 2003}, booktitle = {Bessy annual report 2003}, publisher = {Bessy}, address = {Berlin}, pages = {408 -- 409}, language = {en} } @misc{LupinaSchroederDabrowskietal., author = {Lupina, Grzegorz and Schroeder, Thomas and Dabrowski, Jarek Marek and Schmeißer, Dieter and Hoffmann, Patrick}, title = {Praseodymium silicate layers with atomically abrupt interface on Si(100)}, series = {Applied Physics Letters}, volume = {87}, journal = {Applied Physics Letters}, number = {5}, issn = {0003-6951}, pages = {S. 092901}, language = {en} } @phdthesis{Lupina, author = {Lupina, Grzegorz}, title = {Praseodymium Silicate high-k dielectrics on Si(001)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-421}, language = {en} } @article{LupinaSchroederSchmeisseretal., author = {Lupina, Grzegorz and Schroeder, Thomas and Schmeißer, Dieter and Dabrowski, Jarek Marek}, title = {Praseodymium Silicate Films on Si(100) for Gate Dielectric Applications: Physical and Electrical Characterization}, 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} } @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{LippertDabrowskiCostinaetal., author = {Lippert, Gunther and Dabrowski, Jarek Marek and Costina, Ioan and Lupina, Grzegorz and Ratzke, Markus and Zaumseil, Peter and M{\"u}ssig, Hans-Joachim}, title = {Morphology and Composition of Praseodymium Based High-k Materials and Their Relevance to Dielectric Properties of Thin-Films}, language = {en} } @misc{ZoellnerDabrowskiZaumseiletal., author = {Z{\"o}llner, Marvin Hartwig and Dabrowski, Jarek Marek and Zaumseil, Peter and Giussani, A. and Schubert, Markus Andreas and Lupina, Grzegorz and Wilkens, Henrik and Wollschl{\"a}ger, Joachim and B{\"a}umer, Marcus and Reichling, M. and Schr{\"o}der, Thomas}, title = {On the unusual stacking behavior of twin-free, type B oriented CeO2(111) films on hexagonal Pr2O3(0001) / Si(111) systems}, series = {Physical Review}, volume = {85}, journal = {Physical Review}, number = {3}, issn = {1098-0121}, doi = {10.1103/PhysRevB.85.035302}, pages = {035302 -- 035311}, language = {en} } @misc{BartolomeoSantandreaGiubileoetal., author = {Bartolomeo, Antonio di and Santandrea, S. and Giubileo, Filippo and Romeo, Francesco and Petrosino, Mario and Citro, R. and Barbara, P. and Lupina, Grzegorz and Schr{\"o}der, Thomas and Rubino, Alfredo}, title = {Effect of back-gate on contact resistance and on channel conductance in graphene-based field-effect transistors}, series = {Diamond and Related Materials}, volume = {38}, journal = {Diamond and Related Materials}, number = {13}, issn = {0925-9635}, pages = {19 -- 23}, language = {en} }