Browsing by Author "Tzeng, W. H."

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Bipolar resistive switching characteristics of Gd2O3 thin film structure
(2011)
Chang, K. M.
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Tzeng, W. H.
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Liu, K. C.
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Chan, Y. C.
;
Kuo, C. C.
The resistive switching (RS) behavior of the Ti/Gd2O3/Pt capacitor structure is fabricated and discussed in this paper. The switching characteristics operated under positive bias exhibits stable switching properties with a condensed voltage and resistance values dispersion, while the switching characteristics becomes unstable and large fluctuation on switching parameters under the negative bias operation. We suggest that the anode electrode plays an important role to the switching characteristics, and might be the causes of the asymmetry of the I-V curves between positive and negative operation. Constant voltage stress measurement is also tested to reveal the switching mechanism of the Gd2O3 film, and the switching mechanism is mainly based on the applied voltage and thermal Joule heat.
Modulation of the Electrical Characteristics of HfOx/TiN RRAM Devices through the Top Electrode Metal
(2010)
Chang, K. M.
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Tzeng, W. H.
;
Liu, K. C.
;
Lai, W. R.
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電子工程學系及電子研究所
The effect of the top electrode on switching characteristics of a HfOx/TiN structure was investigated. From the electrical conduction analysis, the conduction mechanism between Pt and Ti was found to be quite different. A potential barrier formed in the Pt/HfOx interface showing the Fowler-Nordheim tunneling at high bias. However, it was not observed in the Ti/HfOx structure. Reactive metal Ti interacted with the underlying HfOx film leading to destruction of the barrier height. As such, the device lost the ability to operate at the mu A compliance current range. Pt/HfOx demonstrated the merit of a large resistance ratio and a low operation current (Ireset = 20 mu A). However, Ti/HfOx exhibited better voltage dispersion at the low resistance state (0.5V dispersion). The electrode plays a dominant role in determining the electrical characteristics of a resistive random access memory (RRAM) device. Therefore, choosing an adequate electrode for RRAM is an important consideration.