Effect of O2 migration in Pt/HfO2/Ti/Pt structure

In this paper, we study the post-fabrication phenomenon of natural oxidation of the Ti layer observed in a Pt/HfO<sub>2</sub>/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 HfO<sub>2</sub> 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 TiO<sub>2</sub> inter-layer, creating a Pt/HfO<sub>2</sub>/TiO<sub>2</sub>/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 10<sup>4</sup> with no observable post-fabrication aging degradation.


Published in:
Journal of Electroceramics, 39, 1-4, 137-142
Year:
2017
Publisher:
Dordrecht, Springer Verlag
ISSN:
1385-3449
Keywords:
Laboratories:


Note: The status of this file is: EPFL only


 Record created 2018-01-09, last modified 2018-12-03

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