Effect of O2- migration in Pt/HfO2/Ti/Pt structure
- 226 Downloads
In this paper, we study the post-fabrication phenomenon of natural oxidation of the Ti layer observed in a Pt/HfO2/Ti/Pt Resistive Random Access Memory (OxRRAM) stack with no external influence. We identify that the resistance ratio decreases by 100 × in a month time period due to the natural oxidation of the Ti layer in contact of the HfO2 layer. We then propose two paths to control both the final properties of the device and the aging process. The first approach consists in carefully optimizing the thickness of the Ti layer to reduce the aging effect. However, the resistance ratio is proportional to the thickness of the layer, leading to an unwanted trade-off between device properties and aging effect. The second approach consists in adding a TiO2 inter-layer, creating a Pt/HfO2/TiO2/Ti/Pt OxRRAM stack that is more stable over time with similar resistive states. The obtained OxRRAM stack presents a resistance ratio in the order of 104 with no observable post-fabrication aging degradation.
KeywordsOxide-based memories RRAMs XPS Aging
The authors would like to acknowledge Pierre Mettraux for his help on XPS analysis, as well as the CMi (EPFL) and Nanofab (UofU) staffs for the help in cleanroom.
- 3.C. Kugeler, C. Nauenheim, M. Meier, A. Rudiger, R. Waser, Fast resistance switching of TiO2 and MSQ thin films for non-volatile memory applications (OxRRAM), Non-Volatile Memory Technology Symposium (2008)Google Scholar
- 4.S. Zuloaga, L. Rui, C. Pai-Yu, Y. Shimeng Yu, Scaling 2-Layer OxRRAM Cross-Point Array Towards 10 Nm Node: A device-circuit co-design, IEEE International Symposium on Circuits and Systems (2015)Google Scholar
- 6.P.-E. Gaillardon, X. Tang, J. Sandrini, M. Thammasack, S. Rahimian Omam, D. Sacchetto, Y. Leblebici, G. De Micheli, A Ultra-Low-Power FPGA Based on Monolithically Integrated OxRRAMs, Design, Automation and Test in Europe Conference (2015)Google Scholar
- 13.F.M. Puglisi, L. Larcher, A. Padovani, P. Pavan, Bipolar Resistive RAM Based on HfO2: Physics, Compact Modeling, and Variability Control, IEEE Journal on Emerging and Selected Topics in Circuits and Systems (2016)Google Scholar
- 14.C. Cagli, J. Buckley, V. Jousseaume, T. Cabout, A. Salaun, H. Grampeix, J.F. Nodin, H. Feldis, A. Persico, J. Cluzel, P. Lorenzi, L. Massari, R. Rao, F. Irrera, F. Aussenac, C. Carabasse, M. Coue, P. Calka, E. Martinez, L. Perniola, P. Blaise, Z. Fang, Y.H. Yu, G. Ghibaudo, D. Deleruyelle, M. Bocquet, ller Mü C., A. Padovani, O. Pirrotta, L. Vandelli, L. Larcher, G. Reimbold, B. de Salvo, Experimental and theoretical study of electrode effects in HfO2 based RRAM, International Electron Devices Meeting 28.7.1–28.7.4 (2011)Google Scholar