Hostname: page-component-76d6cb85b7-6jg5l Total loading time: 0 Render date: 2026-07-22T21:12:04.449Z Has data issue: false hasContentIssue false

Observation of filament formation process of Cu/HfO2/Pt ReRAM structure by hard x-ray photoelectron spectroscopy under bias operation

Published online by Cambridge University Press:  20 January 2012

Takahiro Nagata*
Affiliation:
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan
Masamitsu Haemori
Affiliation:
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan
Yoshiyuki Yamashita
Affiliation:
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan; and NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148, Japan
Hideki Yoshikawa
Affiliation:
NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148, Japan
Keisuke Kobayashi
Affiliation:
NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148, Japan
Toyohiro Chikyow
Affiliation:
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan
*
a)Address all correspondence to this author. e-mail: NAGATA.Takahiro@nims.go.jp
Get access

Abstract

We have demonstrated resistance switching using polycrystalline HfO2 film with a Cu top electrode for nonvolatile memory applications and revealed the Cu diffusion into the HfO2 layer during the filament formation process. Resistive switching was clearly observed in the Cu/HfO2/Pt structure by performing a current–voltage measurement. The current step from a high-resistive state to a low-resistive state was of the order of 103–104 Ω, which provided a sufficient on/off ratio for use as a switching device. The filament formation process was investigated by employing hard x-ray photoelectron spectroscopy under bias operation. The application of a bias to the structure reduced the Cu2O state at the interface and the intensity ratio of Cu 2p3/2/Hf 3d5/2, providing evidence of Cu2O reduction and Cu diffusion into the HfO2 layer. These results also provide evidence that the resistance switching of the Cu/HfO2/Pt structure originates in a solid electrolyte (nanoionics model) containing Cu ions.

Information

Type
Invited Feature Paper
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable