@misc{HoZschechSchmeisseretal., author = {Ho, Paul S. and Zschech, Ehrenfried and Schmeißer, Dieter and Meyer, Moritz Andreas and Huebner, Rene and Hauschildt, Meike and Zhang, Lijuan and Gall, Martin and Kraatz, Matthias}, title = {Scaling effects on microstructure and reliability for cu interconnects}, language = {en} } @inproceedings{KlocekFriedrichSchmeisseretal., author = {Klocek, Jolanta and Friedrich, Daniel and Schmeißer, Dieter and Hecker, Michael and Zschech, Ehrenfried}, title = {The stability of C60 and its derivatives upon handling in microsystems technologies}, 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 = {43 -- 46}, language = {en} } @misc{ZschechGeislerRinderknechtetal., author = {Zschech, Ehrenfried and Geisler, Holm and Rinderknecht, Jochen and Schneider, Gerd and Spolenak, Ralph and Schmeißer, Dieter}, title = {Nano-scale analysis using synchrotron-radiation: Applications in the semiconductor industry}, series = {Current nanoscience}, volume = {4}, journal = {Current nanoscience}, number = {3}, issn = {1573-4137}, pages = {256 -- 266}, language = {en} } @inproceedings{SchmeisserZhengHimpseletal., author = {Schmeißer, Dieter and Zheng, Fan and Himpsel, Franz J. and Engelmann, Hans-J{\"u}rgen and Zschech, Ehrenfried}, title = {Silicate Formation at the Interface of High-k Dielectrics and Si(001) Surfaces}, language = {en} } @article{SchmeisserZschech, author = {Schmeißer, Dieter and Zschech, Ehrenfried}, title = {Silicate Formation at the Interface of Hf-Oxide and Pr-Oxide as a High-k Dielectric and Si(001) surfaces}, language = {en} } @incollection{ZschechEngelmannOhsiek, author = {Zschech, Ehrenfried and Engelmann, Hans-J{\"u}rgen and Ohsiek, Susanne}, title = {Advanced MOSFET Gate Dielectrics for High-Performance Microprocessors: Materials Selection and Analytical Challenges}, editor = {Kramer, B.}, doi = {http://dx.doi.org/10.1007/11423256_30}, language = {en} } @inproceedings{ZschechStegmannSchmeisseretal., author = {Zschech, Ehrenfried and Stegmann, Heiko and Schmeißer, Dieter and Hoffmann, Patrick}, title = {Chemical Bonding, Permittivity, and Elastic Properties in Locally Modified Organosilicate Glass}, language = {en} } @misc{SzyszkiewiczWarzechaStecDejaetal., author = {Szyszkiewicz-Warzecha, Krzysztof and Stec, Jakub and Deja, Jan and Łagosz, Artur and G{\´o}rska, Anna and Kutukova, Kristina and Zschech, Ehrenfried and Filipek, Robert}, title = {3D Multi-Ion Corrosion Model in Hierarchically Structured Cementitious Materials Obtained from Nano-XCT Data}, series = {Materials}, volume = {16}, journal = {Materials}, number = {14}, issn = {1996-1944}, doi = {10.3390/ma16145094}, abstract = {Corrosion of steel reinforcements in concrete constructions is a worldwide problem. To assess the degradation of rebars in reinforced concrete, an accurate description of electric current, potential and concentrations of various species present in the concrete matrix is necessary. Although the concrete matrix is a heterogeneous porous material with intricate microstructure, mass transport has been treated in a homogeneous material so far, modifying bulk transport coefficients by additional factors (porosity, constrictivity, tortuosity), which led to so-called effective coefficients (e.g., diffusivity). This study presents an approach where the real 3D microstructure of concrete is obtained from high-resolution X-ray computed tomography (XCT), processed to generate a mesh for finite element method (FEM) computations, and finally combined with a multi-species system of transport and electric potential equations. This methodology allows for a more realistic description of ion movements and reactions in the bulk concrete and on the rebar surface and, consequently, a better evaluation of anodic and cathodic currents, ultimately responsible for the loss of reinforcement mass and its location. The results of this study are compared with a state-of-the-art model and numerical calculations for 2D and 3D geometries.}, language = {en} } @misc{LechowskiKutukovaGrenzeretal., author = {Lechowski, Bartlomiej and Kutukova, Kristina and Grenzer, Joerg and Panchenko, Iuliana and Krueger, Peter and Clausner, Andre and Zschech, Ehrenfried}, title = {Laboratory X-ray Microscopy of 3D Nanostructures in the Hard X-ray Regime Enabled by a Combination of Multilayer X-ray Optics}, series = {Nanomaterials}, volume = {14}, journal = {Nanomaterials}, number = {2}, issn = {2079-4991}, doi = {10.3390/nano14020233}, abstract = {High-resolution imaging of buried metal interconnect structures in advanced microelectronic products with full-field X-ray microscopy is demonstrated in the hard X-ray regime, i.e., at photon energies > 10 keV. The combination of two multilayer optics—a side-by-side Montel (or nested Kirkpatrick-Baez) condenser optic and a high aspect-ratio multilayer Laue lens—results in an asymmetric optical path in the transmission X-ray microscope. This optics arrangement allows the imaging of 3D nanostructures in opaque objects at a photon energy of 24.2 keV (In-Kα X-ray line). Using a Siemens star test pattern with a minimal feature size of 150 nm, it was proven that features < 150 nm can be resolved. In-Kα radiation is generated from a Ga-In alloy target using a laboratory X-ray source that employs the liquid-metal-jet technology. Since the penetration depth of X-rays into the samples is significantly larger compared to 8 keV photons used in state-of-the-art laboratory X-ray microscopes (Cu-Kα radiation), 3D-nanopattered materials and structures can be imaged nondestructively in mm to cm thick samples. This means that destructive de-processing, thinning or cross-sectioning of the samples are not needed for the visualization of interconnect structures in microelectronic products manufactured using advanced packaging technologies. The application of laboratory transmission X-ray microscopy in the hard X-ray regime is demonstrated for Cu/Cu6Sn5/Cu microbump interconnects fabricated using solid-liquid interdiffusion (SLID) bonding.}, language = {en} } @misc{KutukovaLechowskiGrenzeretal., author = {Kutukova, Kristina and Lechowski, Bartlomiej and Grenzer, Joerg and Krueger, Peter and Clausner, Andr{\´e} and Zschech, Ehrenfried}, title = {Laboratory High-Contrast X-ray Microscopy of Copper Nanostructures Enabled by a Liquid-Metal-Jet X-ray Source}, series = {Nanomaterials}, volume = {14}, journal = {Nanomaterials}, number = {5}, issn = {2079-4991}, doi = {10.3390/nano14050448}, abstract = {High-resolution imaging of Cu/low-k on-chip interconnect stacks in advanced micro-electronic products is demonstrated using full-field transmission X-ray microscopy (TXM). The comparison of two lens-based laboratory X-ray microscopes that are operated at two different photon energies, 8.0 keV and 9.2 keV, shows a contrast enhancement for imaging of copper nanostructures embedded in insulating organosilicate glass of a factor of 5 if 9.2 keV photons are used. Photons with this energy (Ga-Kα radiation) are generated from a Ga-containing target of a laboratory X-ray source applying the liquid-metal-jet technology. The 5 times higher contrast compared to the use of Cu-Kα radiation (8.0 keV photon energy) from a rotating anode X-ray source is caused by the fact that the energy of the Ga-Kα emission line is slightly higher than that of the Cu-K absorption edge (9.0 keV photon energy). The use of Ga-Kα radiation is of particular advantage for imaging of copper interconnects with dimensions from several 100 nm down to several 10 nm in a Cu/SiO2 or Cu/low-k backend-of-line stack. Physical failure analysis and reliability engineering in the semiconductor industry will benefit from high-contrast X-ray images of sub-µm copper structures in microchips.}, language = {en} }