Resistive Switching in Hf_0.5Zr_0.5O₂ ferroelectric tunnel junctions

by Milena Cervo Sulzbach, Multifunctional Thin Films and Complex Structures (MULFOX) group (ICMAB, CSIC)

Date: Wednesday, 26 May 2021
Time: 3 pm
Venue: ICMAB Seminar Room "Carles Miravitlles" and online session by Zoom. Register here to attend by Zoom.

Abstract: HfO₂-based oxides have been explored as ReRAM elements due to their resistance change caused by redox reactions. However, the discovery of ferroelectricity in doped-HfO₂ opens doors to use polarization reversal as a phenomenon to control the resistance. Here, Hf_0.5Zr_0.5O₂ epitaxial ferroelectric tunnel junctions with thickness smaller than 5 nanometers are studied. Electrical and structural analyses have allowed identifying the coexistence of genuine ferroelectric switching and ionic-like motion as mechanisms to induce resistance change in the same junction. By engineering the film's microstructure, the ferroelectric switching was optimized and the ionic motion was suppressed. In addition, its memristive behavior were. The results presented indicate HZO tunnel junctions are feasible alternatives for application in non-volatile memories.

Supervisor:

• Josep Fontcuberta, MULFOX, ICMAB, CSIC

PhD Committee:

• President: Gustau Catalán, Institut Català de Nanociència i Nanotecnologia ICN2 - Spain
• Secretary: Anna Palau, Institut de Ciència de Materials de Barcelona ICMAB-CSIC - Spain
• Vocal: Christian Rinaldi, Politecnico di Milano - Italy

Tutor UAB:

• Jordi Sort Viñas, Physics Department, UAB

University: Universitat Autònoma de Barcelona (UAB)
PhD Programme: Physics