A Combined Ab Initio and Experimental Study on the Nature of Conductive Filaments in Pt/HfO2/Pt Resistive Random Access Memory

Through ab initio calculations, we propose that the conductive filaments in Pt/HfO 2 /Pt resistive random access memories are due to HfO x suboxides, possibly tetragonal, where x ≤ 1.5. The electroforming process is initiated by a continuous supply of oxygen Frenkel defect pairs through an electroch...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on electron devices 2014-05, Vol.61 (5), p.1394-1402
Main Authors: Xue, Kan-Hao, Traoré, Boubacar, Blaise, Philippe, Fonseca, Leonardo, Vianello, Elisa, Molas, Gabriel, de Salvo, Barbara, Ghibaudo, Gérard, Magyari-Kope, Blanka, Nishi, Yoshio
Format: Article
Language:English
Subjects:
Engineering Sciences
Micro and nanotechnologies
Microelectronics
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Through ab initio calculations, we propose that the conductive filaments in Pt/HfO 2 /Pt resistive random access memories are due to HfO x suboxides, possibly tetragonal, where x ≤ 1.5. The electroforming process is initiated by a continuous supply of oxygen Frenkel defect pairs through an electrochemical process. The accumulation of oxygen vacancies leads to metallic suboxide phases, which remain conductive even as ultranarrow 1-nm 2 filaments embedded in an insulating HfO 2 matrix. Our experiments further show that the filaments remain as major leakage paths even in the OFF-state. Moreover, thermal heating may increase the OFF-state resistance, implying that there are oxygen interstitials left in the oxide layer, which may recombine with the oxygen vacancies in the filaments at high temperature.
ISSN:0018-9383
DOI:10.1109/TED.2014.2312943