TY - JOUR
T1 - Bias induced Cu ion migration behavior in resistive change memory structure observed by hard X-ray photoelectron spectroscopy
AU - Nagata, Takahiro
AU - Yamashita, Yoshiyuki
AU - Yoshikawa, Hideki
AU - Imura, Masataka
AU - Oh, Seungjun
AU - Kobashi, Kazuyoshi
AU - Chikyow, Toyohiro
N1 - Publisher Copyright:
© 2015 The Japan Society of Applied Physics.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - The Cu ion migration behavior of a Pt/Cu/HfO2/Pt structure, which is an oxide-based resistive random access memory (ReRAM) and exhibits resistance switching behavior at voltages of ±0.8 V, was investigated by hard X-ray photoelectron spectroscopy under a bias operation. A forward bias application, during switching from a high resistive state (HRS) to a low resistive state, reduced the Cu2O bonding state at the interface and the intensity ratio of Cu 2p3/2/Hf 3d5/2 (Cu/Hf) by 23 ± 5%, providing evidence of reductions in unintentionally formed Cu2O and Cu diffusion into the HfO2 layer. After switching to HRS again, Cu/Hf increased by 15 ± 5%, indicating that the Cu ion moved back to the top electrode side, though oxygen showed no bias voltage dependence. Consequently, the Cu ion has a key role in the switching. We directly observed the Cu migration behavior related to the resistive change at the Cu/HfO2 interface under bias operation.
AB - The Cu ion migration behavior of a Pt/Cu/HfO2/Pt structure, which is an oxide-based resistive random access memory (ReRAM) and exhibits resistance switching behavior at voltages of ±0.8 V, was investigated by hard X-ray photoelectron spectroscopy under a bias operation. A forward bias application, during switching from a high resistive state (HRS) to a low resistive state, reduced the Cu2O bonding state at the interface and the intensity ratio of Cu 2p3/2/Hf 3d5/2 (Cu/Hf) by 23 ± 5%, providing evidence of reductions in unintentionally formed Cu2O and Cu diffusion into the HfO2 layer. After switching to HRS again, Cu/Hf increased by 15 ± 5%, indicating that the Cu ion moved back to the top electrode side, though oxygen showed no bias voltage dependence. Consequently, the Cu ion has a key role in the switching. We directly observed the Cu migration behavior related to the resistive change at the Cu/HfO2 interface under bias operation.
UR - http://www.scopus.com/inward/record.url?scp=84930740462&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84930740462&partnerID=8YFLogxK
U2 - 10.7567/JJAP.54.06FG01
DO - 10.7567/JJAP.54.06FG01
M3 - Article
AN - SCOPUS:84930740462
SN - 0021-4922
VL - 54
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
IS - 6
M1 - 06FG01
ER -