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1. Intrinsic RESET speed limit of valence change memories

Author

von Witzleben, Moritz, Wiefels, Stefan, Kindsmüller, Andreas, Stasner, Pascal, Berg, Fenja, Cüppers, Felix, Hoffmann-Eifert, Susanne, Waser, Rainer, Menzel, Stephan, and Böttger, Ulrich

Subjects
Physics - Applied Physics
Abstract

During the last decade, valence change memory (VCM) has been extensively studied due to its promising features, such as a high endurance and fast switching times. The information is stored in a high resistive state (logcial '0', HRS) and a low resistive state (logcial '1', LRS). It can also be operated in two different writing schemes, namely a unipolar switching mode (LRS and HRS are written at the same voltage polarity) and a bipolar switching mode (LRS and HRS are written at opposite voltage polarities). VCM, however, still suffers from a large variability during writing operations and also faults occur, which are not yet fully understood and, therefore, require a better understanding of the underlying fault mechanisms. In this study, a new intrinsic failure mechanism is identified, which prohibits RESET times (transition from LRS to HRS) faster than 400 ps and possibly also limits the endurance. We demonstrate this RESET speed limitation by measuring the RESET kinetics of two valence change memory devices (namely Pt/TaO$_\mathrm{x}$/Ta and Pt/ZrO$_\mathrm{x}$/Ta) in the time regime from 50 ns to 50 ps, corresponding to the fastest writing time reported for VCM. Faster RESET times were achieved by increasing the applied pulse voltage. Above a voltage threshold it was, however, no longer possible to reset both types of devices. Instead a unipolar SET (transition from HRS to LRS) event occurred, preventing faster RESET times. The occurrence of the unipolar SET is attributed to an oxygen exchange at the interface to the Pt~electrode, which can be suppressed by introducing an oxygen blocking layer at this interface, which also allowed for 50 ps fast RESET times., Comment: 27 pages, 18 figures and 69 references

Published
2021
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2. Picosecond Multilevel Resistive Switching in Tantalum Oxide Thin Films

Author

Böttger, Ulrich, von Witzleben, Moritz, Havel, Viktor, Fleck, Karsten, Rana, Vikas, Waser, Rainer, and Menzel, Stephan

Subjects
Physics - Applied Physics
Abstract

The increasing demand for high-density data storage leads to an increasing interest in novel memory concepts with high scalability and the opportunity of storing multiple bits in one cell. A promising candidate is the redox-based resistive switch repositing the information in form of different resistance states. For reliable programming, the underlying physical parameters need to be understood. We reveal that the programmable resistance states are linked to internal series resistances and the fundamental nonlinear switching kinetics. The switching kinetics of Ta$_{2}$O$_{5}$-based cells was investigated in a wide range over 15 orders of magnitude from 250 ps to 10$^{5}$ s. We found strong evidence for a switching speed of 10 ps which is consistent with analog electronic circuit simulations. On all time scales, multi-bit data storage capabilities were demonstrated. The elucidated link between fundamental material properties and multi-bit data storage paves the way for designing resistive switches for memory and neuromorphic applications., Comment: Compiled PDF should contain 24 pages, 5 figures and 50 references

Published
2019
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3. Investigation of the large-signal electromechanical behavior of ferroelectric HfO2–CeO2 thin films prepared by chemical solution deposition.

Author

Lübben, Jan, Berg, Fenja, and Böttger, Ulrich

Subjects
FERROELECTRIC thin films, CHEMICAL solution deposition, PIEZOELECTRIC thin films, FERROELECTRIC materials, CHEMICAL properties, ELECTRIC fields
Abstract

In this work, the piezoelectric properties of chemical solution deposition derived ferroelectric HfO2–CeO2 thin films deposited on platinized silicon substrates are investigated. Large-signal strain-field measurements show an effective piezoelectric coefficient of approximately d 33 , eff = 12.7 pm / V for 17 mol. % cerium under bipolar excitation and d 33 , eff = 8 pm / V under unipolar excitation. Progressive bipolar electric field cycling leads to a reduction in the overall field induced strain although no fatigue with regards to the polarization is observed. To explain this, we propose a model explanation based on changes in the polarization reversal pathway from a primarily ferroelastic, i.e., 90 ° domain wall mediated switching, to a 180 ° type switching. Furthermore, unipolar strain-field measurements reveal a negative intrinsic piezoelectric coefficient in the absence of any ferroelastic contribution, confirming theoretical predictions. The results suggest that the ferroelastic contribution to the field-induced strain needs to be stabilized in Hafnia-based ferroelectric materials to make them more feasible for micro-electromechanical systems. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Influence of moisture on the ferroelectric properties of sputtered hafnium oxide thin films.

Author

Berg, Fenja, Kopperberg, Nils, Lübben, Jan, Valov, Ilia, Wu, Xiaochao, Simon, Ulrich, and Böttger, Ulrich

Subjects
HAFNIUM oxide films, HAFNIUM oxide, MONTE Carlo method, FERROELECTRICITY, REACTIVE sputtering
Abstract

While the influence of various fabrication parameters during deposition on the ferroelectricity of hafnium oxide has been extensively studied, the effect of different atmospheres on the actual switching process has not yet been investigated. In this work, we characterized the ferroelectric properties of undoped hafnium oxide prepared by reactive sputtering under three different atmospheres: dry oxygen/nitrogen, wet nitrogen, and vacuum conditions. We found a significant correlation between dry and wet atmospheres and resulting polarization. Specifically, we observed a direct effect on ferroelectric switching when the film was exposed to dry atmospheres and vacuum, resulting in a higher electric field necessary to initialize the wake-up effect due to an initial imprint effect. Increasing the amount of wet nitrogen during switching decreased the imprint and lowered the necessary voltage required for the wake up. We present a simple model that explains and discusses the incorporation of moisture and its resulting consequences on the ferroelectric properties of hafnium oxide. Additionally, kinetic Monte Carlo simulations showed that the addition of protons to the oxide thin film leads to a lowering of the potential and to a redistribution of protons and oxygen vacancies, which reduces the initial imprint. [ABSTRACT FROM AUTHOR]

Published
2023
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8. Contributors

Author

Balke, Nina, primary, Batra, Rohit, additional, Böttger, Ulrich, additional, Breyer, Evelyn T., additional, Do Kim, Keum, additional, Fancher, Chris M., additional, Fengler, Franz, additional, Fujii, Shosuke, additional, Funakubo, Hiroshi, additional, Griesche, David, additional, Grimley, Everett D., additional, Gruverman, Alexei, additional, Hoffmann, Michael, additional, Hwang, Cheol Seong, additional, Hyun, Seung Dam, additional, Ihlefeld, Jon F., additional, Johnson, Brienne, additional, Jones, Jacob L., additional, Kersch, Alfred, additional, Kim, Han Joon, additional, Künneth, Christopher, additional, Larcher, Luca, additional, LeBeau, James M., additional, Lee, Young Hwan, additional, Migita, Shinji, additional, Mikolajick, Thomas, additional, Mueller, Johannes, additional, Mulaosmanovic, Halid, additional, Park, Min Hyuk, additional, Pešić, Milan, additional, Ramprasad, Rampi, additional, Rossetti, George A., additional, Saitoh, Masumi, additional, Schenk, Tony, additional, Schneller, Theodor, additional, Schroeder, Uwe, additional, Shibayama, Shigehisa, additional, Shimizu, Takao, additional, Slesazeck, Stefan, additional, Starschich, Sergej, additional, Stolichnov, Igor, additional, Tian, Xuan, additional, Toriumi, Akira, additional, and Xu, Lun, additional

Published
2019
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26. Intrinsic RESET Speed Limit of Valence Change Memories

Author

von Witzleben, Moritz, primary, Wiefels, Stefan, additional, Kindsmüller, Andreas, additional, Stasner, Pascal, additional, Berg, Fenja, additional, Cüppers, Felix, additional, Hoffmann-Eifert, Susanne, additional, Waser, Rainer, additional, Menzel, Stephan, additional, and Böttger, Ulrich, additional

Published
2021
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29. Nanosession: Valence Change Memories - Redox Mechanism and Modelling

Author

Ielmini, D., primary, Larentis, S., additional, Balatti, S., additional, Nardi, F., additional, Gilmer, D., additional, Menzel, Stephan, additional, Marchewka, Astrid, additional, Böttger, Ulrich, additional, Waser, Rainer, additional, Balcells, Ll., additional, Pomar, A., additional, Galceran, R., additional, Konstantinovic, Z., additional, Peña, L., additional, Bozzo, B., additional, Sandiumenge, F., additional, Martinez, B., additional, Riess, Ilan, additional, Kalaev, Dima, additional, Lim, Hyungkwang, additional, Jang, Ho-Won, additional, Hwang, Cheol Seong, additional, Jeong, Doo Seok, additional, Schmelzer, Sebastian, additional, Schneegans, Olivier, additional, Mai, Van Huy, additional, Moradpour, Alec, additional, Auban-Senzier, Pascale, additional, Pasquier, Claude, additional, Wang, Kang, additional, Franger, Sylvain, additional, Revcolevschi, Alexandre, additional, Svoukis, Efthymios, additional, Giapintzakis, John, additional, Lecoeur, Philippe, additional, Aubert, Pascal, additional, Agnus, Guillaume, additional, Maroutian, Thomas, additional, Salot, Raphaël, additional, and Chrétien, Pascal, additional

Published
2013
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30. Poster: Polar Dielectrics, Optics, and Ionics

Author

Jin Kim, Yu, primary, Hyuk Park, Min, additional, Joon Kim, Han, additional, Seok Jeong, Doo, additional, Jiang, Anquan, additional, Seong Hwang, Cheol, additional, Schmelzer, Sebastian, additional, Böttger, Ulrich, additional, Waser, Rainer, additional, Liu, X., additional, Lu, H., additional, Burton, J. D., additional, Wang, Y., additional, Bark, C. W., additional, Zhang, Y., additional, Kim, D. J., additional, Stamm, A., additional, Lukashev, P., additional, Felker, D. A., additional, Folkman, C. M., additional, Gao, P., additional, Rzchowski, M. S., additional, Pan, X. Q., additional, Eom, C. B., additional, Gruverman, A., additional, Tsymbal, E. Y., additional, Politova, E. D., additional, Kaleva, G. M., additional, Mosunov, A. V., additional, Sadovskaya, N. V., additional, Segalla, A. G., additional, Mandal, Dipankar, additional, Henkel, Karsten, additional, Das, Suken, additional, Schmeißer, Dieter, additional, Abdel Halim, K. S., additional, Khedr, M. H., additional, Farghali, A. A., additional, Nasr, M. I., additional, Soliman, N. K., additional, Onbasli, Mehmet, additional, Goto, T., additional, Kim, D. H., additional, Bi, L., additional, Dionne, G. F., additional, Ross, C. A., additional, Schneller, Theodor, additional, Goodwin, Simon, additional, Di Quarto, Francesco, additional, Di Franco, Francesco, additional, Santamaria, Monica, additional, Yuan, Hongtao, additional, Ishida, Y., additional, Koizumi, K., additional, Shimotani, H., additional, Kanai, K., additional, Akaike, K., additional, Kubozono, Y., additional, Tsukazaki, A., additional, Kawasaki, M., additional, Shin, S., additional, Iwasa, Y., additional, De Souza, Roger A., additional, Metlenko, Veronika, additional, Schraknepper, Henning, additional, Ramadan, Amr, additional, Grope, B. O. H., additional, Grieshammer, S., additional, Koettgen, J., additional, Martin, M., additional, Shibuya, Taizo, additional, Yasuoka, Kenji, additional, Mirbt, Susanne, additional, Sanyal, Biplab, additional, Aoki, Yoshitaka, additional, Martin, Manfred, additional, Merkle, R., additional, Shirpour, M., additional, Rahmati, B., additional, Sigle, W., additional, van Aken, P. A., additional, Maier, J., additional, Sobolev, N. A., additional, Azevedo, A. M., additional, Bazarov, V. V., additional, Zhiteytsev, E. R., additional, Khaibullin, R. I., additional, Griesche, David, additional, Otsuka, Yusuke, additional, Pithan, Christian, additional, Dornseiffer, Jürgen, additional, Lustfeld, H., additional, Pithan, C., additional, and Reißel, M., additional

Published
2013
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31. Poster: Memristive Systems

Author

Ho Yoon, Jung, primary, Jung, Hyung-Suk, additional, Hwan Lee, Min, additional, Hwan Kim, Gun, additional, Ji Song, Seul, additional, Yeong Seok, Jun, additional, Jean Yoon, Kyung, additional, Seong Hwang, Cheol, additional, Besland, M.-P., additional, Tranchant, J., additional, Souchier, E., additional, Moreau, P., additional, Salmon, S., additional, Corraze, B., additional, Janod, E., additional, Cario, L., additional, Zazpe, Raúl, additional, Ungureanu, Mariana, additional, Llopis, Roger, additional, Golmar, Federico, additional, Stoliar, Pablo, additional, Casanova, Félix, additional, Eduardo Hueso, Luis, additional, Hermes, C., additional, Wimmer, M., additional, Menzel, S., additional, Fleck, K., additional, Rana, V., additional, Salinga, M., additional, Böttger, U., additional, Bruchhaus, R., additional, Wuttig, M., additional, Waser, R., additional, Lentz, F., additional, Rösgen, B., additional, Selle, T., additional, Marchewka, Astrid, additional, Menzel, Stephan, additional, Böttger, Ulrich, additional, Waser, Rainer, additional, Hoskins, Brian, additional, Alibart, Fabien, additional, Strukov, Dmitri, additional, Pellegrino, Luca, additional, Manca, Nicola, additional, Kanki, Teruo, additional, Tanaka, Hidekazu, additional, Biasotti, Michele, additional, Bellingeri, Emilio, additional, Sergio Siri, Antonio, additional, Marré, Daniele, additional, M. Padilha, Antonio Claudio, additional, Martini Dalpian, Gustavo, additional, Reily Rocha, Alexandre, additional, Prodromakis, Themistoklis, additional, Salaoru, Iulia, additional, Khiat, Ali, additional, Toumazou, Christopher, additional, Gale, Ella M., additional, Madhavan, A., additional, Adam, G., additional, Alibart, F., additional, Gao, L., additional, Strukov, D. B., additional, Wamwangi, D., additional, Welnic, W., additional, Gholipour, Behrad, additional, Huang, Chung-Che, additional, Anastasopoulos, Alexandros, additional, Al-Saab, Feras, additional, Hayden, Brian E., additional, Hewak, Daniel W., additional, Lan, Rui, additional, Endo, Rie, additional, Kuwahara, Masashi, additional, Kobayashi, Yoshinao, additional, Susa, Masahiro, additional, Baumeister, Paul, additional, Wortmann, Daniel, additional, Blügel, Stefan, additional, Mazzarello, Riccardo, additional, Li, Yan, additional, Zhang, Wei, additional, Ronneberger, Ider, additional, Simon, Ronnie, additional, Gallus, Jens, additional, Bessas, Dimitrios, additional, Sergueev, Ilya, additional, Wille, Hans-Christian, additional, Pierre Hermann, Raphaël, additional, Luckas, Jennifer, additional, Rausch, Pascal, additional, Krebs, Daniel, additional, Zalden, Peter, additional, Boltz, Janika, additional, Raty, Jean-Yves, additional, Salinga, Martin, additional, Longeaud, Christophe, additional, Wuttig, Matthias, additional, Kim, Haeri, additional, Kim, Dong-Wook, additional, Phark, Soo-Hyon, additional, Hong, Seungbum, additional, Park, C., additional, Herpers, A., additional, Verbeeck, J., additional, Egoavil, R., additional, Borgatti, F., additional, Panaccione, G., additional, Offi, F., additional, Dittmann, R., additional, Clima, Sergiu, additional, Sankaran, Kiroubanand, additional, Mees, Maarten, additional, Yin Chen, Yang, additional, Goux, Ludovic, additional, Govoreanu, Bogdan, additional, Wouters, Dirk J., additional, Kittl, Jorge, additional, Jurczak, Malgorzata, additional, Pourtois, Geoffrey, additional, Calka, P., additional, Martinez, E., additional, Delaye, V., additional, Lafond, D., additional, Audoit, G., additional, Mariolle, D., additional, Chevalier, N., additional, Grampeix, H., additional, Cagli, C., additional, Jousseaume, V., additional, Guedj, C., additional, Shrestha, Pragya, additional, Ochia, Adaku, additional, Cheung, Kin. P., additional, Campbell, Jason, additional, Baumgart, Helmut, additional, Harris, Gary, additional, Scherff, Malte, additional, Meyer, Bjoern, additional, Scholz, Julius, additional, Hoffmann, Joerg, additional, Jooss, Christian, additional, Xiao, Bo, additional, Tada, Tomofumi, additional, Gu, Tingkun, additional, Tawara, Arihiro, additional, Watanabe, Satoshi, additional, Young, Tai-Fa, additional, Yang, Ya-Liang, additional, Chang, Ting-Chang, additional, Hsu, Kuang-Ting, additional, Chen, Chao-Yu, additional, Burkert, A, additional, Valov, I., additional, Staikov, G., additional, van den Hurk, Jan, additional, Valov, Ilia, additional, Tappertzhofen, Stefan, additional, van der Hurk, Jan, additional, Hoskins, B., additional, Kim, Gun Hwan, additional, Seok, Jun Yeong, additional, Ho Yoon, Jeong, additional, Yoon, Jung Ho, additional, Yoon, Kyung Jin, additional, Shuai, Yao, additional, Wu, Chuangui, additional, Zhang, Wanli, additional, Zhou, Shengqiang, additional, Bürger, Danilo, additional, Slesazeck, Stefan, additional, Mikolajick, Thomas, additional, Helm, Manfred, additional, Schmidt, Heidemarie, additional, Gale, Ella, additional, Pearson, David, additional, Kitson, Stephen, additional, Adamatzky, Andrew, additional, Costello, Ben de Lacy, additional, Lehtonen, Eero, additional, Poikonen, Jussi, additional, Laiho, Mika, additional, Kanerva, Pentti, additional, Lim, Hyungkwang, additional, Jang, Ho-won, additional, Jeong, Doo Seok, additional, Cao, Xun, additional, Jiang, Meng, additional, Zhang, Feng, additional, Liu, Xinjun, additional, Jin, Ping, additional, Zhang, Kai, additional, Tangirala, Madhavi, additional, Kittiwatanakul, Salinporn, additional, Lu, Jiwei, additional, Wolf, Stuart, additional, Pallem, Venkateswara, additional, Dussarrat, Christian, additional, Pinto, S., additional, Krishna, R., additional, Dias, C., additional, Pimentel, G., additional, Oliveira, G. N. P., additional, Teixeira, J. M., additional, Aguiar, P., additional, Titus, E., additional, Gracio, J., additional, Ventura, J., additional, and Araujo, J. P., additional

Published
2013
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36. Low leakage ZrO2 based capacitors for sub 20 nm dynamic random access memory technology nodes.

Author

Pešić, Milan, Knebel, Steve, Geyer, Maximilian, Schmelzer, Sebastian, Böttger, Ulrich, Kolomiiets, Nadiia, Afanas'ev, Valeri V., Kyuho Cho, Changhwa Jung, Jaewan Chang, Hanjin Lim, Mikolajick, Thomas, and Schroeder, Uwe

Subjects
DYNAMIC random access memory, CAPACITORS, SEMICONDUCTOR storage devices, DIELECTRIC devices, ELECTRIC capacity
Abstract

During dynamic random access memory (DRAM) capacitor scaling, a lot of effort was put searching for new material stacks to overcome the scaling limitations of the current material stack, such as leakage and sufficient capacitance. In this study, very promising results for a SrTiO3 based capacitor with a record low capacitance equivalent thickness value of 0.2 nm at target leakage current are presented. Due to the material properties of SrTiO3 films (high vacancy concentration and low band gap), which are leading to an increased leakage current, a physical thickness of at least 8 nm is required at target leakage specifications. However, this physical thickness would not fit into an 18 nm DRAM structure. Therefore, two different new approaches to develop a new ZrO2 based DRAM capacitor stack by changing the inter-layer material from Al2O3 to SrO and the exchange of the top electrode material from TiN to Pt are presented. A combination of these two approaches leads to a capacitance equivalent thickness value of 0.47 nm. Most importantly, the physical thickness of <5 nm for the dielectric stack is in accordance with the target specifications. Detailed evaluation of the leakage current characteristics leads to a capacitor model which allows the prediction of the electrical behavior with thickness scaling. [ABSTRACT FROM AUTHOR]

Published
2016
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48. Simulation of multilevel switching in electrochemical metallization memory cells.

Author

Menzel, Stephan, Böttger, Ulrich, and Waser, Rainer

Subjects
*ELECTROCHEMICAL metallizing, *SIMULATION methods & models, *QUANTUM tunneling, *CATIONS, *FARADAY effect, *CHARGE transfer, *EQUATIONS, *ELECTRODES
Abstract

We report on a simulation model for bipolar resistive switching in cation-migration based memristive devices. The model is based on the electrochemical driven growth and dissolution of a metallic filament. The origin of multilevel switching is proposed to be direct tunneling between the growing filament and the counter electrode. An important result of our parameter simulation studies is that different materials show the same experimental multilevel behavior. Our model fully reproduces the experimental data and allows for an explanation of the transition from bipolar to nonpolar switching. [ABSTRACT FROM AUTHOR]

Published
2012
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49. Structural investigations of Pt/TiOx electrode stacks for ferroelectric thin film devices.

Author

Jiang-Li Cao, Solbach, Axel, Klemradt, Uwe, Weirich, Thomas, Mayer, Joachim, Horn-Solle, Herbert, Böttger, Ulrich, Schorn, Peter J., Schneller, T., and Waser, Rainer

Subjects
FERROELECTRIC thin films, TITANIUM compounds, THIN films, ELECTRODES, TRANSMISSION electron microscopy
Abstract

Effects of the thermal treatment and the fabrication process of Pb(Zr0.3Ti0.7)O3 (PZT) thin films using chemical solution deposition on Pt/TiOx electrode stacks were investigated using complementary analytical techniques including atomic force microscopy (AFM), x-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and grazing incidence x-ray reflectivity of synchrotron radiation. The surface and interface structures of the Pt/TiOx electrode stacks with different thermal treatments, and the PZT/Pt/TiOx sample were examined. The propagation of Pt hillocks on the bare Pt/TiOx electrode stacks upon the annealing was observed. AFM observations also revealed that the upper surface of the Pt bottom electrode under PZT thin film became rougher than that of the bare Pt electrode with the same thermal history. Global structural information including the density, surface or interface root-mean-square roughness, and thickness of each constituent layer in the samples were determined using x-ray reflectivity. A density decrease of the Pt layer upon the annealing or during the fabrication of PZT thin films was found from fitting the specular reflectivity, and further confirmed by the negative shift of the Yoneda peak of Pt in the diffuse reflectivity. The formation of Pt hillocks on the bare Pt electrodes was attributed to the compressive stress during the high-temperature annealing caused by the limited incorporation of Ti and O into the Pt layer. Roughening of the PZT/Pt interface was ascribed to the interaction between the compressive stress in Pt and the indentation by the PZT crystallization and grain growth during the annealing. [ABSTRACT FROM AUTHOR]

Published
2006
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50. Mechanical force sensors using organic thin-film transistors.

Author

Darlinski, Grzegorz, Böttger, Ulrich, Waser, Rainer, Klauk, Hagen, Halik, Marcus, Zschieschang, Ute, x00FC;nter#Schmid, G&, and Dehm, Christine

Subjects
*THIN film transistors, *THIN films, *SOLID state electronics, *ORGANIC semiconductors, *SEMICONDUCTORS, *THIN film devices, *TRANSISTORS
Abstract

The pressure dependence of pentacene (C22H14) transistors with solution-processed polyvinylphenol gate dielectric on glass substrates is investigated by applying uniaxial mechanical pressure with a needle. We found that organic thin-film transistors are sensitive to applied pressure inherently. The measurements reveal a reversible current dependence of the transfer characteristics where the drain current is switching between two states. Experimental and simulation results suggest that switch-on voltage and interface resistance are affected. The change takes seconds, hinting at trap states being responsible for the effect. [ABSTRACT FROM AUTHOR]

Published
2005
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