| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Tuesday Sessions |
| Session EM+MI+NS+SS+TF-TuA |
| Session: | High-k Oxides for MOSFETs and Memory Devices II/Oxides and Dielectrics for Novel Devices and Ultra-dense Memory I |
| Presenter: | J. Robertson, Cambridge University, UK |
| Correspondent: | Click to Email |
Resistive random access memories (RRAM)have great potential as future non-volatile memories with a faster read and write time than Flash memory. RRAM works by the forming of a conductive filament across a resistive film between the electrodes, which is then SET and RESET between its conductive and resistive states [1-2]. Typical films are oxides such as TiO2 , Ta2O5 and HfO2,and the conductive filament is believed to consistent of a percolation path of oxygen vacancies. Recently there have been various models of this oxygen vacancy path, in terms of molecular dynamics [3], or ordered vacancy structures [4]. Here we use an ordered model of vacancies in HfO2 or TiO2, as in a local M2O3 structure in the MO2 matrix. In Ti2O3, the Ti atoms form an ordered line of Ti-Ti dimers along the c axis, and the bonding state stabilises the Ti3+ state along the path. The transition between the ordered and disordered phase of dimers describes the low to high resistivity state of RRAM, as in the metal-insulator transition in Ti2O3.
1 R Waser et al, Adv Mater 21 2632 (2009)
2 G Bersuker, SISC (2012)
3 S Clima et al, App Phys Lett 100 133102 (2012)
4 K Kamiya, M Yang, S Park, B M Kope, Y Nishi, M Niwa, K Shiraishi, App Phys Lett 100 073502 (2012)