@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} } @inproceedings{SeifarthWilkeWalczyketal., author = {Seifarth, Olaf and Wilke, A. and Walczyk, Christian and Dabrowski, Jarek Marek and Zaumseil, Peter and Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {Band gap and electronic structure determination with XAS and UPS of thin Pr-oxide films on Si(111)}, series = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, booktitle = {Proceedings of 15th Workshop on Dielectrics in Microelectronics, Bad Saarow, 23 - 25 June 2008, Bad Saarow (Berlin)}, pages = {285 -- 286}, 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{DudekLupinaKozłowskietal., author = {Dudek, Piotr T. and Lupina, Grzegorz and Kozłowski, Grzegorz and Zaumseil, Peter and Bauer, Jakob and Fursenko, Oksana and Dabrowski, Jarek Marek and Schmidt, R. and Lippert, Gunther and M{\"u}ssig, Hans-Joachim and Schr{\"o}der, Thomas and Schmeißer, Dieter and Zschech, Ehrenfried}, title = {Atomic-scale engineering of future high-k dynamic random access memory dielectrics: The example of partial Hf substitution by Ti in BaHfO3}, series = {Journal of Vacuum Science and Technology / B}, volume = {29}, journal = {Journal of Vacuum Science and Technology / B}, number = {1}, issn = {2166-2754}, language = {en} } @inproceedings{SeifarthWalczykLupinaetal., author = {Seifarth, Olaf and Walczyk, Christian and Lupina, Grzegorz and Dabrowski, Jaroslaw and Weidner, G{\"u}nter and Zaumseil, Peter and Schmeißer, Dieter and Storck, Peter and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {On the electronic and dielectric characterisation of thin cubic PrO2 layers on Silicon}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 43}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 196}, abstract = {For the integration of 100 \% Ge onto the Si platform, a buffer oxide approach has been developed recently, using rare earth oxides to tune the lattice constant between the Si and the Ge. Among these buffer oxides, PrO2 is a prospective candidate with high quality crystalline growth on Si, moderated by an interfacial Pr-silicate between. In order to specify electronic properties of thin PrO2 and its interface on Si(111), especially the width of the band gap, we performed synchrotron radiation based XPS, UPS and XAS measurements at the U49/2 PGM 2 beamline at BESSY II and correlate the results with our structural characterisation performed by TEM and XRD. In order to evaluate the dielectric properties of thin PrO2 layers on Si(111), we performed temperature-, time-, voltage-, and layer thickness-dependent leakage current measurements (J-V). Here, we identified relaxation behaviour in the leakage current, successfully addressed to defect like states inside the Pr-silicate interface layer, corroborated by frequency dependent capacitance versus voltage (C-V) measurements.}, language = {en} } @inproceedings{SeifarthWalczykLupinaetal., author = {Seifarth, Olaf and Walczyk, Christian and Lupina, Grzegorz and Zaumseil, Peter and Schmeißer, Dieter and M{\"u}ssig, Hans-Joachim and Schroeder, Thomas}, title = {The electronic band diagram of thin PrO2(111) / Pr-silicate buffers on Si(111) and its relevance to dielectric properties}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft, Reihe 6, Bd. 44}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 136}, abstract = {Thin dielectric buffers of cubic PrO2(111) on Si(111) are ideally suited to integrate Ge onto Si by moderating the lattice mismatch between the materials. The leakage current across this dielectric buffer is strongly influenced by the electronic band diagram and defects inside the band gap. Therefore, we measured the band offsets, band gaps and defect positions by means of synchrotron radiation based photoemission spectroscopy techniques (XPS and XAS) with special emphasis on the Pr-silicate interface. In a next step we compare the spectroscopic data with information from dielectric studies, based on temperature dependent leakage current studies. We observe a close relation between dielectric properties and the electronic structure.}, language = {en} } @misc{LippertDabrowskiOberbecketal., author = {Lippert, Gunther and Dabrowski, Jarek Marek and Oberbeck, Lars and Schroeder, Uwe and Costina, Ioan and Lupina, Grzegorz and Ratzke, Markus and Zaumseil, Peter and M{\"u}ssig, Hans-Joachim}, title = {Morphology and composition of selected high-k materials and their relevance to dielectric properties of thin films}, series = {Journal of the electrochemical society}, volume = {155}, journal = {Journal of the electrochemical society}, number = {5}, issn = {1945-7111}, doi = {10.1149/1.2875741}, pages = {G97 -- G114}, language = {en} }