TY - GEN A1 - Zöllner, Christian A1 - Adriano, Christian M. A1 - Wietheger, Simon A1 - Lambers, Leen A1 - Giese, Holger ED - Kühn, Thomas ED - Sousa, Vasco T1 - Tool support for the teaching of state-based behavior modeling T2 - MODELS '22: Proceedings of the 25th International Conference on Model Driven Engineering Languages and Systems: Companion Proceedings N2 - Modeling tools are commonly adopted in classrooms. However, complex state-based behavioral models still pose a challenge for students to understand and validate, mostly because of the intricate semantics of these models. We investigated this challenge and developed dedicated tool support in the form of a validation framework based on the YAKINDU Statechart Tools. Our validation framework simulates environments that interact with the code generated from statecharts as a means to animate various open-ended scenarios and predefined test cases that challenge the students' models. This enables short and user-friendly feedback cycles, which lowers the barrier for students to learn state-based behavioral models. We designed the validation framework to be extensible and made it available as an open source project together with two example environments and complete teaching materials. We report on our experiences in two undergraduate modeling courses (approx. 100 students each). Our results are promising in the sense that we detected positive effects of tool adoption and a surprising lack thereof, which we discuss w.r.t. lessons learned and future work. KW - modeling KW - education KW - statecharts KW - simulation KW - validation framework Y1 - 2022 SN - 978-1-4503-9467-3 U6 - https://doi.org/10.1145/3550356.3556501 SP - 87 EP - 94 PB - Association for Computing Machinery CY - New York, NY, United States ER - TY - GEN A1 - Reiter, Sebastian A1 - Han, Weijia A1 - Mai, Christian A1 - Spirito, Davide A1 - Jose, Josmy A1 - Zöllner, Marvin Hartwig A1 - Fursenko, Oksana A1 - Schubert, Markus Andreas A1 - Stemmler, Ivo A1 - Wenger, Christian A1 - Fischer, Inga Anita T1 - Titanium Nitride Plasmonic Nanohole Arrays for CMOS-Compatible Integrated Refractive Index Sensing: Influence of Layer Thickness on Optical Properties T2 - Plasmonics Y1 - 2023 U6 - https://doi.org/10.1007/s11468-023-01810-3 SN - 1557-1963 SP - 1 EP - 13 ER - TY - GEN A1 - Förster, Stefan A1 - Schenk, Sebastian A1 - Zollner, Eva Maria A1 - Krahn, Oliver A1 - Chiang, Cheng-Tien A1 - Schumann, Florian O. A1 - Bayat, Alireza A1 - Schindler, Karl-Michael A1 - Trautmann, Martin A1 - Hammer, René A1 - Meinel, Klaus A1 - Adeagbo, Waheed A. A1 - Hergert, Wolfram A1 - Flege, Jan Ingo A1 - Falta, Jens A1 - Ellguth, Martin A1 - Tusche, Christian A1 - DeBoissieu, Marc A1 - Muntwiler, Matthias A1 - Gerber, Thomas A1 - Widdra, Wolf T1 - Quasicrystals and their Approximants in 2D Ternary Oxides T2 - Physia Status Solidi B N2 - 2D oxide quasicrystals (OQCs) are recently discovered aperiodic, but well-ordered oxide interfaces. In this topical review, an introduction to these new thin-film systems is given. The concept of quasicrystals and their approximants is explained for BaTiO3 and SrTiO3 derived OQCs and related periodic structures in these 2D oxides. In situ microscopy unravels the high-temperature formation process of OQCs on Pt(111). The dodecagonal structure is discussed regarding tiling statistics and tiling decoration based on the results of atomically resolved scanning tunneling microscopy and various diffraction techniques. In addition, angle-resolved ultraviolet photoemission spectroscopy and X-ray photoelectron spectroscopy results prove a metallic character of the 2D oxide. KW - approximants KW - dodecagonal oxide quasicrystals KW - oxide quasicrystals KW - tiling statistics Y1 - 2020 U6 - https://doi.org/10.1002/pssb.201900624 SN - 0370-1972 SN - 1521-3951 VL - 257 IS - 7 ER - TY - GEN A1 - Niu, Gang A1 - Zöllner, Marvin Hartwig A1 - Schröder, Thomas A1 - Schäfer, Andreas A1 - Jhang, Jin-Hao A1 - Zielasek, Volkmar A1 - Bäumer, Marcus A1 - Wilkens, Henrik A1 - Wollschläger, Joachim A1 - Olbrich, Reinhard A1 - Lammers, Christian A1 - Reichling, Michael T1 - Controlling the physics and chemistry of binary and ternary praseodymium and cerium oxide systems T2 - Physical Chemistry Chemical Physics Y1 - 2015 U6 - https://doi.org/10.1039/C5CP02283E SN - 1463-9084 SN - 1463-9076 VL - 17 IS - 38 SP - 24513 EP - 24540 ER - TY - GEN A1 - Mahmoodinezhad, Ali A1 - Morales, Carlos A1 - Naumann, Franziska A1 - Plate, Paul A1 - Meyer, Robert A1 - Janowitz, Christoph A1 - Henkel, Karsten A1 - Kot, Małgorzata A1 - Zöllner, Marvin Hartwig A1 - Wenger, Christian A1 - Flege, Jan Ingo T1 - Low-temperature atomic layer deposition of indium oxide thin films using trimethylindium and oxygen plasma T2 - Journal of Vacuum Science and Technology A N2 - Indium oxide (InxOy) thin films were deposited by plasma-enhanced atomic layer deposition (PEALD) using trimethylindium and oxygen plasma in a low-temperature range of 80–200 °C. The optical properties, chemical composition, crystallographic structure, and electrical characteristics of these layers were investigated by spectroscopic ellipsometry (SE), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), as well as current-voltage and capacitance-voltage measurements. The SE results yielded a nearly constant growth rate of 0.56 Å per cycle and a thickness inhomogeneity of ≤1.2% across 4-in. substrates in the temperature range of 100–150 °C. The refractive index (at 632.8 nm) was found to be 2.07 for the films deposited at 150 °C. The PEALD-InxOy layers exhibit a direct (3.3 ± 0.2 eV) and an indirect (2.8 ± 0.1 eV) bandgap with an uptrend for both with increasing substrate temperature. Based on XPS characterization, all InxOy samples are free of carbon impurities and show a temperature-dependent off-stoichiometry indicating oxygen vacancies. XRD diffraction patterns demonstrate an onset of crystallization at 150 °C. Consistent with the optical, XPS, and XRD data, the films deposited at ≥150 °C possess higher electrical conductivity. Our findings prove that a low-temperature PEALD process of InxOy is feasible and promising for a high-quality thin-film deposition without chemical impurities on thermally fragile substrates. KW - Indium oxide KW - Plasma-enhanced atomic layer deposition KW - X-ray photoelectron spectroscopy KW - Ellipsometry KW - X-ray diffraction KW - Electrical properties Y1 - 2021 U6 - https://doi.org/10.1116/6.0001375 SN - 0734-2101 SN - 1520-8559 VL - 39 IS - 6 ER - TY - GEN A1 - Kuschel, Olga A1 - Dieck, Florian A1 - Wilkens, Henrik A1 - Gevers, Sebastian A1 - Rodewald, Jari A1 - Otte, Christian A1 - Zöllner, Marvin Hartwig A1 - Niu, Gang A1 - Schröder, Thomas A1 - Wollschläger, Joachim T1 - Plasma Enhanced Complete Oxidtation of Ultrathin Epitaxial Praseodymia Films on Si(111) T2 - Materials Y1 - 2015 U6 - https://doi.org/10.3390/ma8095312 SN - 1996-1944 VL - 8 IS - 9 SP - 6379 EP - 6390 ER - TY - GEN A1 - Janowitz, Christoph A1 - Mahmoodinezhad, Ali A1 - Kot, Małgorzata A1 - Morales, Carlos A1 - Naumann, Franziska A1 - Plate, Paul A1 - Zöllner, Marvin Hartwig A1 - Bärwolf, Florian A1 - Stolarek, David A1 - Wenger, Christian A1 - Henkel, Karsten A1 - Flege, Jan Ingo T1 - Toward controlling the Al2O3/ZnO interface properties by in situ ALD preparation T2 - Dalton Transactions N2 - An Al2O3/ZnO heterojunction was grown on a Si single crystal substrate by subsequent thermal and plasma-assisted atomic layer deposition (ALD) in situ. The band offsets of the heterointerface were then studied by consecutive removal of the layers by argon sputtering, followed by in situ X-ray photoelectron spectroscopy. The valence band maximum and conduction band minimum of Al2O3 are found to be 1.1 eV below and 2.3 eV above those of ZnO, resulting in a type-I staggered heterojunction. An apparent reduction of ZnO to elemental Zn in the interface region was detected in the Zn 2p core level and Zn L3MM Auger spectra. This suggests an interface formation different from previous models. The reduction of ZnO to Zn in the interface region accompanied by the creation of oxygen vacancies in ZnO results in an upward band bending at the interface. Therefore, this study suggests that interfacial properties such as the band bending as well as the valence and conduction band offsets should be in situ controllable to a certain extent by careful selection of the process parameters. KW - ALD heterojunction KW - band alignement KW - ZnO KW - Al2O3 KW - interface properties Y1 - 2022 U6 - https://doi.org/10.1039/D1DT04008A SN - 1477-9234 SN - 1477-9226 VL - 51 SP - 9291 EP - 9301 ER - TY - GEN A1 - Zöllner, Marvin Hartwig A1 - Richard, Marie-Ingrid A1 - Chahine, Gilbert A. A1 - Zaumseil, Peter A1 - Reich, Christian A1 - Capellini, Giovanni A1 - Montalenti, Francesco A1 - Marzegalli, Anna A1 - Xie, Ya-Hong A1 - Schülli, Tobias U. A1 - Häberlen, Maik A1 - Storck, Peter A1 - Schroeder, Thomas T1 - Imaging structure and composition homogeneity of 300 mm SiGe virtual substrates for advanced CMOS applications by scanning X-ray diffraction microscopy T2 - ACS Applied Materials and Interfaces Y1 - 2015 U6 - https://doi.org/10.1021/am508968b SN - 1944-8252 VL - 7 IS - 17 SP - 9031 EP - 9037 ER -