Research Areas

The research areas of the institute comprise (1) technologies for the integration of electroceramic materials into microelectronics and nanoelectronics, (2) dielectric and ferroelectric properties of oxide ceramics, and (3) the defect structure in the vicinity of internal and external interfaces in oxides. These areas are complementary to the research areas of the Institute for Electronic Materials 2 (IWE 2) at the Aachen Technical University (RWTH). Project groups often comprise staff members and students from both institutes.

As an updated and significantly enlarged version of the 32^nd IFF-Ferienschule which we organized in 2001, we completed the edition of the textbook Nanoelectronics and Information Technology - Advanced Electronic Materials and Novel Devices. This textbook as well as the next IFF-Ferienschule on Fundamentals of Nanoelectronics are supporting the preparation of the new research program Nanoelectronic Systems in the frame-work of the HGF research area Key Technologies. One aspect of the new organization within the HGF will put more emphasis on the interdisciplinary of the research activities. In this respect, our activities are strengthening the bridge between the IFF and the ISG (Institut für Schichten und Grenzflächen).

Integration Technologies and Scaling Effects

The major project in the area of integration technologies and scaling effects is our HGF project ŽPiccolo – Scaling Effects in Integrated Electroceramic MaterialsŽ (2000 – 2003). This project is embedded in the former information technology program PGI (Physikalische Grundlagen der Informationstechnologie) of the Research Center Jülich. Beyond the (1) Institut für Elektrokeramische Materialien, the (2) Institut für Mikrostrukturforschung IMF headed by K. Urban, (3) the Theorie III, headed by H. Müller-Krumbhaar, and (4) the Ion Technology (IT) group at the ISG headed by S. Mantl are involved. Several national and international universities and research centers participate in "Piccolo", too. The main focus of the proposal "Piccolo" is a fundamental as well as applied research on scaling effects of electroceramic materials. Today, typically polycrystalline films exhibit grain sizes much smaller than the feature sizes of the microelectronic devices. However, along with the sustaining trend towards further miniaturization, the decreasing feature sizes in microelectronic technology will approach the typical crystallite sizes of the perovskite-type oxide structures. Specific scaling effects are anticipated along this route, due to the long-range nature of the ferroelectric interaction of the oxides involved. The project aims at an (1) elucidation of the physical origin of these scaling effects, (2) an exploitation and extension of the limits to which the ferroelectric properties and high permittivities of the oxides involved can be used, and (3) the development of technological design rules for the integration of the perovskite-type oxides on a decreasing scale. The spectrum of designated results of the project comprises (semiquantitative) models for the superparaelectric limit of ferroelectric (FE) oxides, the dead layer at interfaces, the phase stability and segregation processes of perovskite films during annealing, the nucleation and growth of films by MOCVD (Metal Organic Chemical Vapor Deposition), recipes for the deposition of single grain capacitors and ultrathin FE films as well as for reactive ion etching and a ferroelectric field-effect transistor (FE-FET) as a demonstrator. Scanning Probe Microscopy (SPM) techniques such as AFM and STM play an essential role in studying interrelationships on a microscopic base. Hence, the project "Piccolo" is an initiative to pursue research on the basic properties of electroceramic materials under scaling and on the relevance of these effects for the integration of perovskite-type oxides into microelectronics.

In cooperation with AIXTRON AG, our multiwafer MOCVD planetary reactor has been upgraded by the TriCent injector system which allows, in principle, the atomic layer-by-layer deposition of ultrathin films. This will be needed in the new Medea+ project which aims at the formation of alternative gate-oxide for future sub-100nm main-stream FETs and is useful as well for our FE-FET project.

As a supplement, we use high pressure oxygen sputtering for the deposition of ultrathin PZT film within the Piccolo project. For the patterning of the ceramic films and electrode / ceramic film stacks, the Reactive Ion Beam Etching (RIBE) technique is employed. In contrast to the situation in the standard Si and compound semiconductor technologies, dry etching processes of oxide ceramics have hardly been investigated yet and therefore represent a research area in which basic studies and industrially funded applied research can be linked in a beneficial manner. The integration processes are complemented by metallization methods based on electron beam and sputter techniques. Within this area, our studies aim at a better understanding of the processes and material parameters which govern the adhesion, the mechanical stress, the microstructure, and their effect on the dielectric and ferroelectric properties.

Furthermore, organic molecules gain importance in electronic applications. In a cooperation with Infineon Technologies and headed by the FZ Karlsruhe, we have started a joint research project on resistive random access memories based on oxidic nanostructures and molecular electronic components.

Dielectric and ferroelectric properties

The second research area focuses on the dielectric and ferroelectric properties of oxide thin films and – for comparison – bulk ceramics, which are being investigated in Jülich as well as in Aachen. The material systems are based on compositions used for practical devices and model systems, e.g. SrTiO₃, BaTiO₃, SrBi₂Ta₂O₉, Pb(Zr,Ti)O₃. One of the research topics is the microscopic understanding of ferroelectric hysteresis including new approaches for the separation of reversible and irreversible contributions to polarisation based on the analysis of frequency-dependent small and large signals.

The polarisation studies are linked to the aging (imprint) phenomenon, i.e. the polarisation-dependent shift of the hysteresis curve with time and to the ferroelectric fatigue process, i. e. the reduction of the remanent polarisation by cycling. Both aging and fatigue processes play an important role in the operation of the novel non-volatile memories (Ferroelectric Random Access Memories, FeRAM). Impedance spectroscopy in the lower GHz regime is employed to determine the relaxation of the ferroelectric domain wall motion and to separate this contribution from the contribution of the crystal lattice. By varying the microstructure of the ceramics and by comparison between bulk ceramics and thin films, the model of Arlt will be extended with respect to the impact on 2D constraints imposed by mechanical stress due to the presence of substrates. The investigations of the ferroelectric properties are now additionally focussed on the scaling properties and nano-size effects. For dielectric ceramics, impedance spectroscopy is used to elucidate the interrelation of extrinsic losses and lattice defects. In the case of ferroelectric materials, existing theories are further developed and extended towards a more quantitative description of the dielectric, piezoelectric, and elastic properties.

Lattice disorder in the vicinity of internal interfaces

Our third research area comprises the lattice disorder in the vicinity of internal interfaces (grain boundaries) and external interfaces (surfaces and electrode interfaces) and their impact on electronic and ionic (oxygen ions and protons) charge transport. In the case of acceptor and donor doped titanate ceramics, the studies are focused on the formation of space charge depletion layers at grain boundaries as well as the related potential barriers and the transport of charge carriers along and across the grain boundary barrier. A hot-pressing technology has been developed to decorate the grain boundary area with additional dopants and to study the influence of these artificial grain boundary states. The coupling of the space-charge formation and the defect equilibria at the surface in the case of donor-doped titanates led us to a comprehensive explanation for long pending questions concerning the redox kinetics.

In some material systems, it is necessary to determine the equilibrium constants of the defect reactions and the diffusion constants of the system in order to create the basis for the research on interfaces. In this respect, the comparison of bulk ceramics and thin films of the same composition is of vital interest. In thin film systems, the significant influence of the electrode metals, the unexpectedly high stability under conditions of dc-voltage-induced resistance degradation, the tolerance of the lattice concerning the incorporation of non-stoichiometries as well as the relationship to nanocrystalline bulk ceramics represent current research topics.

Head: Prof. Dr.-Ing. Rainer Waser
Secretary: Maria Garcia

Tel. +49(0)2461 61 5811; Fax: +49(0)2461 61 2550

e-mail: r.waser@fz-juelich.de / m.garcia@fz-juelich.de

Scientists	Field of Activity	No.
Dr. R. Dittmann	Pulsed laser deposition of epitaxial oxide thin films, multilayers and nanostructures	23.42.0
Dr. P. Ehrhart	MOCVD methods for electroceramic thin films; X-ray diffraction	23.42.0
Dr. R. Elsebrock	Processing of electroceramic bulk materials; microwave characterization; dielectric properties	23.42.0
Dr. S. Hoffmann-Eifert	High-permittivity electroceramic thin films: MOCVD, dielectric properties, charge transport, defect chemistry	23.42.0
Dr. S. Karthäuser	Self-assembly processes of oxidic and metallic nanostructures	23.42.0
Dr. H. Kohlstedt	Reactive ion beam etching of ceramic and metallic materials, magnetic and ferroelectric tunnel junctions	23.42.0
Dr. P. Meuffels	Synthesis and processing of electroceramic materials; studies of the defect chemistry	23.10.2
Dr. Ch. Pithan	Processing of hot pressed nanocrystalline and grain boundary decorated bulk electroceramics	23.10.2
Prof. T. Schober	High temperature proton conduction, ionic conduction, fuel cell studies, impedance spectroscopy, transmission electron microscopy	23.10.2
Dr. H. Schroeder	Technology and properties of (metal) electrodes for electroceramic thin films; mechanical properties and electromigration in thin films and interconnects	23.42.0
Dr. K. Szot	Study of the surface layer of perovskite materials of ABO3 structure	23.42.0
Prof. R. Waser	Electronic oxides and integration of electroceramic thin films	23.42.0

Technical Engineers
H. Bierfeld	Ceramic technology and sputtering techniques	23.10.2
DI J. Friedrich	Thermogravimetric analysis; Transmission electron microscopy	23.10.2
M. Gebauer	Metal organic chemical vapor deposition (MOCVD) of oxides; electrical measuring setups for atomic force microscopy (AFM)	23.42.0
M. Gerst	Measuring techniques; network administration
DI H. Haselier	Metallization and thin film technology; clean-room technology	23.42.0
B. Hermanns	RIBE, sputtering of magnetic materials	23.42.0
DI H. John	Clean-room technology, microlithography and optical laboratory; LRP	23.42.0
DI C. Makovicka	Ceramic technology; powder processing	23.10.2

PhD Students
M. Fitsilis (Univ. of Thessaloniki)	Simulation and design concepts of ferroelectric field effect transistor circuits	23.42.0
R. Ganster (TH Aachen)	MOCVD growth of alkaline earth titanate-zirconate thin films; optimization of growth processes and electrical characterization	23.42.0
A. Gerber (Uni Köln)	Epitaxial ferroelectric layers on silicon substrates and their use as field effect transistors	23.42.0
B. Lüssem (TH Aachen)	Technology of molecular-electronic test chips	23.42.0
Y. Mustafa (TH Aachen)	Circuit design of ferroelectric memories	23.42.0
Ch. Ohly (TH Aachen)	Electrical conductivity characteristics of nanocrystalline and thin film titanates under changing oxygen ambients	23.42.0
St. Regnery (TH Aachen)	MOCVD planetary reactor processes	23.42.0
J. Rodriguez (Uni Köln)	Ferroelectric capacitors with oxide electrodes and tunneling	23.42.0
S. Stein (Uni Köln)	Spin injection devices	23.42.0

Gradunts
M. Weides (Uni Köln)	Brillouin light scattering on magnetic tunnel junctions	23.42.0
F. Peter (TH Aachen)	Characterization of scanning force microscopy cantilever for local piezoresponse measurements	23.42.0

Guest Scientist
Dr. N. Pertsev A.F. Ioffe Institute St. Petersburg, Russia	Theoretical calculations on the effects of strain and stress on the dielectric response of ferroelectric thin films grown on sole substrates	23.42.0
Dr. W. Hong Xi'an Jiaotong Univ, China	Microwave ceramics and devices	23.42.0

Post-Doc
Dr. X. Guo	Near-interface defect chemistry of doped titanates	23.10.2
Dr. A. Magrez	Synthesis of ceramic proton conductors and construction of a fuel cell	23.10.2
Dr. A. Teren	Alternative gate oxides: MOCVD, characterization and optimization of film properties	23.42.0
Dr. R. Thomas	Evaluation and optimization of modified precursors for the MOCVD of complex oxide thin films	23.42.0
Dr. E. Vasco Matias	Nucleation and growth of epitaxial thin films and nanostructures by pulsed laser deposition	23.42.0

Bachhofer,H.*; Reisinger,H.*; Steinlesberger,G.*; Nagel,N.*; Cerva,H.*; von Philipsborn,H.*; Schroeder,H.; Waser,R.
Interfacial layers and their effect on leakage current in MOCVD-deposited SBT thin films
Integrated ferroelectrics, 39 (2002), S. 189

Bachhofer,H.*; Reisinger,H.*; Steinlesberger,G.*; Nagel,N.*; Cerva,H.*; von Philipsborn,H.; Schroeder,H.; Waser,R.
Interfacial layers and their effect on leakage current in MOCVD-deposited SBT thin films
Integrated ferroelectrics, 39 (2002), S. 289

Ehrhart,P.; Fitsilis,F.; Regnery,S.; Waser,R.; Schienle,F.; Schumacher,M.*; Juergensen,H.*; Krumpen,W.
Growth of (Ba,Sr)TiO3 thin films by MOCVD : stoichiometry effects
Integrated ferroelectrics, 45 (2002), S. 59 - 68

Ellerkmann,U.*; Liedtke,R.*; Waser,R.
Influence of the film-electrode interface in thin-film capacitors
Ferroelectrics, 271 (2002), S. 315 - 320

Emelyanov,A. Y.*; Pertsev,S.*; Hoffmann-Eifert,S.; Boettger,U.*; Waser,R.
Grain-boundary effect on the Curie-Weiss law of ferroelectric ceramics and polycrystalline thin films : calculation by the method of effective medium
Journal of electroceramics, 9 (2002), S. 5 - 16

Ganpule,C. S.; Nagaranjan,V.; Hill,B. K.; Roytburd,A.L.; Williams,E.D.; Ramesh,R.; Alpay,S. P.; Roelofs,A.; Waser,R.; Eng,L. M.
Imaging three-dimensional polarization in epitaxial polydomain ferroelectric thin films
Journal of applied physics, 91 (2002), 3, S. 1477 - 1481

Grossmann,M.*; Lohse,O.*; Bolten,D.*; Boettger,U.*; Schneller,T.*; Waser,R.
The interface screening model as origin of imprint in PbZrx/Ti1-x/O3 thin films 1 : dopant, illumination, and bias dependence
Journal of applied physics, 92 (2002), S. 2680 -2687

Hofer,C.*; Hoffmann,M.*; Boettger,U.*; Waser,R.
Relaxors as high-E- materials for multilayer and thin film capactors
Ferroelectrics, 270 (2002), S. 179 - 184

Hoffmann,M.*; Hofer,C.*; Schneller,T.*; Böttger,U.*; Waser,R.
Preparation and ageing behavior of chemical-solution-deposited (PbMg(0.33)Nb(0,67)O3)1-x-(PbTiO3)x thin films without seeding layers
Journal of the American Ceramic Society, 85 (2002), S. 1867 - 1869

Hölbling,T.*; Waser,R.
Simulation of the charge transport across grain boundaries in P-type SrTiO3 ceramics
Ferroelectrics, 268 (2002), S. 215 - 220

Hölbling,T.*; Waser,R.
Simulation of the charge transport across grain boundaries in p-type SrTiO3 ceramics under dc load : Debye relaxation and dc bias dependence of long-term conductivity
Journal of applied physics, 91 (2002), 5, S. 3037 - 3043

Jia,C.L.; Rodriguez - Contreras,J.*; Poppe,U.; Kohlstedt,H.*; Waser,R.; Urban,K.
Lattice strain and lattice expansion of the SrRuO3 layers in SrRuO3/PbTr0.52Ti0.48O3/SrRuO3 multilayers thin films
Journal of applied physics, 92 (2002), 1, S. 101

Kueppers,H.*; Leuerer,T.*; Schnakenberg,U.*; Mokwa,W.*; Hoffmann,M.*; Schneller,T.*; Boettger,U.*; Waser,R.
PZT thin films for piezoelectric microactuator applications
Sensors and actuators A, 97-98 (2002), S. 680 - 684

Ohly,C.; Hoffmann-Eifert,S.; Szot,K.; Waser,R.
Defects in alkaline earth titanate thin films - the conduction behavior of doped BST
Integrated ferroelectrics, 38 (2001), S. 229 - 237

Prume,K.*; Franken,K.*; Böttger,U.*; Waser,R.; Maier,H.*
Modelling and numerical simulation of the electrical, mechanical and thermal coupled behaviour of MLCs
Journal of the European Ceramic Society, 22 (2002), S. 1285 - 1296

Quin,Y.L.*; Jia,C.L.*; Urban,K.; Liedtke,R.*; Waser,R.
Structural and morphologic evolution of Pt/Ba0,7Sr0,3TiO3/Pt capacitors with annealing processes
Journal of applied physics, 80 (2002), 15 , S. 2728 - 2730

Ritter,S.; Hoffmann-Eifert,S.; Bolten,D.
(Pb1-xBax)TiO3 thin films prepared by liquid delivery MOCVD : influence of the process parameters on film formation and electrical properties
Ferroelectrics, 268 (2002), S. 563 - 568

Roelofs,A.*; Pertsev,N.A.*; Waser,R.; Schlaphof,F.*; Eng,L. M.*; Ganpule,C.*
Depolarization-field-mediated 180° switching in ferroelectric thin films with 90 ° domains
Journal of applied physics, 80 (2002), 8, S. 1424 - 1426

Schneller,T.*; Waser,R.
Chemical solution deposition of ferroelectric thin films - state-of-the-art and recent trends
Ferroelectrics, 267 (2002), S. 293 – 301

Steinlesberger,G.*; Reisinger,H.*; Bachhofer,H.*; Schroeder,H.; Werner,W.*
Dielectric relaxation and charge carrier transport mechanisms in (Ba, SR) TiO3 thin films
Integrated ferroelectrics, 38 (2001), S. 249
 

Book chapter

Rodriguez Contreras,J.; Schubert,J.; Poppe,U.; Trithaveesak,O.; Szot,K.; Buchal,Ch.; Kohlstedt,H.; Waser,R.
Structural and ferroelectric properties of epitaxial PbZr 0,52 Ti 0,48 O3 and Ba TiO3 thin films prepared on SrRuO3/SrTiO3(100) substrates
Materials Research Society Symposium proceedings. - 688 (2002). - S. C8.10

Kügeler,C.*; Hoffmann,M.*; Böttger,U.*; Waser,R.
Integration, electrical and electromechanical properties of PZT and PMN-Pt thin films for MEMS applications
Proceedings of SPIE. - 4699 (2002). - S. 114 - 123

Schroeder,H.; Schmitz,S.
Leakage current measurements of STO and BST thin films interpreted by the 'dead' layer model
14th International Ferroelectrics (ISIF) 2002
Nara, Japan

Schneller,T.*; Waser,R.
Contribution to the microscopic understanding of the chemical mechanisms in solution based PZT thin film deposition
1. Working Group Meeting : Cost 528
Hamburg

Schober,T.
Applications of oxidic high temperature proton conductors
11th International Conference on Proton Conductors, SSPC11
Guildford, UK

Schober,T.
On the use of Pd filters on proton conducting SOFC ceramics
9th Euro Conference on Ionics
Ixia, Rhodos

Schober,T.
Solid state iIonics applications in vacuum technology
OSSEP Workshop der ESF on SOFC and Proton Conductivity
Roskilde, DK

Schroeder,H.
Deposition methods
MRS Fall Meeting 2002 : Tutorial on Ferroelectric Thin Films
Boston, Mass.

Schroeder,H.
Electro-optical devices
MRS Fall Meeting 2002 : Tutorial on Ferroelectric Thin Films
Boston, Mass.

Schroeder,H.
Ausgewählte Kapitel der Metallphysik
Vertiefungsfach II : Fakultät für Bergbau, Hüttenwesen und Geowissenschaften der RWTH Aachen
WS 01/02
 

Invited talks

Haegel,F.H.; Schwuger,M.J.; Pithan,C.; Waser,R.
Electroceramic materials made from nanoparticle powders - investigation of properties related to industrial application
National Meeting of the American Chemical Society : Symposium of Fundamentals and Applications of Uniform Fine Particles

Hoffmann-Eifert,S.; Ohly,C.; Schubert,J.; Waser,R.
The effect of microstructure on the high temperature conductivity of strontium titanate thin films
78th International Bunsen Discussion Meeting on Complex Oxides : Defect Chemistry, Transport and Chemical Reaction
Vaals, Niederlande

Hoffmann-Eifert,S.; Ohly,C.; Waser,R
The correlation between internal interfaces and the high temperature conduction behavior of nanocrystalline and thin film titanates
MRS Fall Meeting 2002
Boston, Mass.

Kügeler,C.*; Hoffmann,M.*; Böttger,U.*; Waser,R.
Integration, electrical and elctromechanical properties of PZT and PMN-Pt thin films for MEMS applications
9th International Symposium on Smart Structures and Materials : SPIE
San Diego, CA

Pithan,C.; Malic,B.*; Ringgaard,E.*; Waser,R.
Processing and characterization of pressure consolidated lead free piezoceramics based on alkaline niobates
International Joint Conference on the Applications of Ferroelectrics 2002
Nara, Japan

Pithan,C.; Waser,R.
Dissemination activities within POLECER
First Annual Meeting of the Thematic European Network on Polar Electroceramics
Interlaken, CH

Ohly,C.; Hoffmann-Eifert,S.; Waser,R.
The role of grain boundaries on the high temperature conduction behavior of nanocrystalline titanate thin films
International Joint Conference on the Applications of Ferroelectrics (IFFF) 2002
Nara, Japan

Regnery,S.; Ehrhart,P.; Fitsilis,F.; Waser,R.; Schienle,F.; Schumacher,M.*; Juergensen,H.*
Nucleation and growth of thin (Ba,Sr)TiO3 films in a MOCVD reactor
MRS Fall Meeting 2002
Boston, Mass.

Rodriguez Contreras,J.; Gerber,A.; Schubert,J.; Poppe,U.; Szot,K.; Jia,C.; Haeni,J.; Biegalski,M.; Kohlstedt,H.; Schlom,D.G.*; Waser,R.
Scaling effects in ferroelectrics
Panamerican Advanced Studies Institute (PASI) Workshop
Rosario, Argentinien

Rodriguez Contreras,J.; Schubert,J.; Poppe,U.; Szot,K.; Jia,C.L.; Kohlstedt,H.; Waser,R.
Scaling effects in ferroelectrics and tunnel junctions with ferroelectric barrier
Panamerican Advanced Studies Institute (PASI) Workshop
Rosario, Argentinien

Rodriguez Contreras,J.; Schubert,J.; Szot,K.; Jia,C.; Haeni,J.; Biegalski,H.; Kohlstedt,H.; Waser,R.; Schlom,D.G.*
Structural and ferroelectric properties of MBE-grown BaTiO3/SrRuO3 thin films
Workshop on Oxide Electronics (WOE 9)
St. Petersburg, Florida

Schneller,T.*; Roelofs,R.*; Waser,R.
CSD derived nanosized single crystalline ferroelectric grains for future non-volatile memory generations
8th International Conference on Ceramic Processing Science
Hamburg
 

Other talks

Waser,R.
Am Vorabend der nächsten Evolutionsstufe?
Infineon Corporate Research Seminar

Waser,R.; Schroeder,H.
Neue Materialien und Bauelemente für die Informationstechnik I
Vertiefungsfach II : Fakultät für Elektrotechnik der RWTH Aachen
WS 01/02

Ohly,C.
The role of grain boundaries on the high temperature conduction behavior of titanate thin films
Sitzung des Wissenschaftlichen Beirats des IFF
Jülich: 21.03.2002

Rodriguez Contreras,J.; Schubert,U.; Poppe,U.; Szot,K.; Kohlstedt,H.; Waser,R.
Influence of patterning method on ferroelectric properties of PbZr 0,52 Ti 0,48 O3
Workshop on Oxidic Surfaces 2002
Halle
 

Posters

Schroeder,H.; Schmitz,S.
Leakage current experiments in STO and BST thin films
MRS Fall Meeting 2002 : Symposium on Ferroelectric Thin Films
Boston, Mass.

Schroeder,H.; Schmitz,S.; Meuffels,P.
Simulation of steady state leakage current in thin films
MRS Fall Meeting 2002 : Symposium on Ferroelectric Thin Films XI
Boston, Mass.

Schroeder,H.; Schmitz,S.; Meuffels,P.; Liedtke,R.
Simulation of leakage current thin films with dead layers
14th International Symposium on Integrated Ferroelectrics (ISIF) 2002
Nara, Japan

Ehrhart,P.; Fitsilis,F.; Regnery,S.; Waser,R.; Schienle,F.; Schumacher,M.*; Juergensen,H.*; Krumpen,W.
Growth of (Ba,Sr)TiO3 thin films by MOCVD : stoichiometry effects
14th International Symposium on Integrated Ferroelectrics
Nara, Japan

Ganster,R.; Hoffmann-Eifert,S.; Waser,R.
Growth of Zr substituted barium titanate thin films from the vapor phase
MRS Fall Meeting 2002 : Symposium Ferroelectric Thin Films XI
Boston, Mass.I01

Karthäuser,S.; Szot,K.; Waser,R.
Termination control of SrTiO3 (100) surfaces
Nato-Workshop : ASINATO Scanning Probe Microscopy
Albufeira, Portugal

Kügeler,C.*; Liedtke,R.*; Waser,R.
Leakage current properties of Ba0,7 Sr0,3 TiO3 thin films depending on the film thickness
ISAF
Nara, Japan

Ohly,C.; Hoffmann-Eifert,S.; Waser,R.
The influence of doping on the high temperature conduction behavior of polycrystalline strontium titanate
78th International Bunsen Discussion Meeting on the Complex Oxides : Defect Chemistry, Transport and Chemiacl Reaction
Vaals, Niederlande

Paul,A.; Damm,T.; Bürgler,D.E.; Stein,S.; Kohlstedt,H.; Grünberg,P.
Correlation of magnetotransport and structure evolution in sputtered Co/Cu multilayers
HGF-Workshop Kondensierte Materie : Forschungszentrum Jülich
Jülich: 06.11.2002

Pithan,C.
POLECER : European thematic network on polar electroceramics
International Joint Conference on the Applications of Ferroelectrics 2002
Nara, Japan

Pithan,C.; Waser,R.; Haegel,F.H.; Dornseiffer,J.
Nanocrystalline BaTiO3-ceramics prepared via microemulsion synthesis - powder characteristics and consolidation behaviour
International Joint Conference on the Applications of Ferroelectrics 2002
Nara, Japan

Pithan,C.; Waser,R.; Malic,B.*; Ringgaard,E.*
Sinter forged lead-free piezoceramics based on alkaline niobates - preparation and properties
Polecer-Workshop on Piezoelectric Materials for the End User
Interlaken, CH

Regnery,S.; Ehrhart,F.; Waser,R.; Ding,Y.; Jia,C.L.; Schumacher,M.*; Schienle,F.; Juergensen,H.
(Ba,Sr)TiO3 thin films growth in a batch processing MOCVD reactor
8th International Conference on Ceramic Processing Science (8th ICCPS)
Hamburg

Rodriguez Contreras,J.; Schubert,J.; Poppe,U.; Szot,K.; Jia,C.L.; Kohlstedt,H.; Waser,R.
Memory device based on a ferroelectric tunnel junction
Device Research Conference (DRC)
Santa Barbara, USA

Rodriguez Contreras,J.; Schubert,J.; Stein,S.; Gerber,A.; Poppe,U.; Szot,K.; Jia,C.L.; Kohlstedt,H.; Waser,R.
Size effects and charge transport through ultrathin ferroelectric barriers
Workshop on Oxide Electronics (WOE 9)

Schneller,T.*; Roelofs,R.*; Waser,R.
Self-assembled growth of nanosized single crystalline ferroelectric grains for future memory applications - a bottom up approach
International Joint Conference on the Applications of Ferroelectrics (IFFF) 2002
Nara, Japan
 

Ph.D. Theses

Sam Schmitz
Abhängigkeit des Leckstromes und der Dielektrizitätskonstanten in SrTiO3- und (Ba,Sr)-TiO3-Dünnschichtkondensatoren von der Kontakt-metallisierung

Fotios Fitsilis
MOCVD of High-K Ceramic Thin Films for the Gbit DRAM Technology
 

Jürgen Rickes
Advanced Circuit Design of Gigabit-Density Ferroelectric Random-Access Memories

Christian Ohly
Nanocrystalline Alkaline earth Titanates and their Electrical Conducitity Characteristics under Changing Oxygen Ambients
 

Patents

Erfindungsmeldung PT 0.2248
Verfahren zur Herstellung einer B-terminierten Oberfläche auf Perowskit-Einkristallen
K.Szot, IFF, W. Speier, WTP