Browsing by Author "Chen, Frederick"

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Effect of ITO electrode with different oxygen contents on the electrical characteristics of HfOx RRAM devices
(2013-09-01)
Zhong, Chia-Wen
;
Tzeng, Wen-Hsien
;
Liu, Kou-Chen
;
Lin, Horng-Chih
;
Chang, Kow-Ming
In this study, the influence of indium tin oxide (ITO) top electrodes with different oxygen contents on the resistive switching characteristics of HfOx/TiN capacitor structure is investigated. Switching parameters, including set and reset voltage values, and high and low resistance values are highly related to the properties of ITO thin films. Higher resistance values in both states can be obtained when ITO thin films with higher oxygen contents are used as top electrodes; such values are accompanied by larger set voltages and fluctuating transient currents during the reset process. Based on the proposed filament model, we suggest that the switching mechanism of HfOx/TiN structure is attributed to the formation and rupture of conducting filamentary paths near the anodic side, which is highly correlated with the properties of the top electrode. The top electrode must be well determined to obtain reliable switching properties. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
Forming-free HfO2 Bipolar RRAM Device with Improved Endurance and High Speed Operation
(2009)
Chen, Yu-Sheng
;
Wu, Tai-Yuan
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Tzeng, Pei-Jer
;
Chen, Pang-Shiu
;
Lee, Heng-Yuan
Investigation of the effect of different oxygen partial pressure to LaAlO3 thin film properties and resistive switching characteristics
(2011-12-01)
Liu, Kou-Chen
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Tzeng, Wen-Hsien
;
Chang, Kow-Ming
;
Huang, Jiun-Jie
;
Lee, Yun-Ju
The pulsed laser deposition and growth of a high-k dielectric lanthanum aluminate LaAlO3 (LAO) thin film on indium tin oxide/glass substrate at different oxygen partial pressure was studied. Based on the pulsed laser deposition growth mechanism, we explain how a difference in the oxygen partial pressure influences the surface roughness, formation of an interfacial layer, and the transparent resistive switching characteristics of LAO thin films. The micro-structure and oxygen concentration difference inside LAO thin films may be the main reason for the difference in electrical and resistive switching properties. Films grown at higher oxygen partial pressure displayed more reliable resistive switching performance, due to the formation of the interfacial layer and a lower concentration of oxygen vacancies. The interfacial layer serves as a good oxygen reservoir and the involvement of more oxygen ions ensures the switching reliability. The migration of oxygen ions between the interfacial layer and the LAO film under applied bias may be the switching mechanism. (C) 2011 Elsevier B. V. All rights reserved.
Resistive switching characteristics of multilayered (HfO2/Al2O3)(n) n=19 thin film
(2012-02-01)
Tzeng, Wen-Hsien
;
Zhong, Chia-Wen
;
Liu, Kou-Chen
;
Chang, Kow-Ming
;
Lin, Horng-Chih
A transparent resistive random access memory used as Indium Tin Oxide (ITO) electrode, ITO/HfO2/Al2O3/center dot center dot center dot/HfO2/Al2O3/ITO capacitor structure is fabricated on glass substrate by atomic layer deposition. The unipolar resistive switching characteristics can be performed by applying the positive- or negative-bias through top electrode, however, the differences of switching and stability in the two different operations can be observed. The diversities of electrical property are attributed to different oxide/ITO interface materials, which influence the current flow of the injected electrons. Crown Copyright (c) 2011 Published by Elsevier B.V. All rights reserved.