Browsing by Author "Hsiao, Yu-Ping"

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Advanced Cu chemical displacement technique for SiO2-based electrochemical metallization ReRAM application
(2014-10-28)
Chin, Fun-Tat
;
Lin, Yu-Hsien
;
You, Hsin-Chiang
;
Yang, Wen-Luh
;
Lin, Li-Min
This study investigates an advanced copper (Cu) chemical displacement technique (CDT) with varying the chemical displacement time for fabricating Cu/SiO2-stacked resistive random-access memory (ReRAM). Compared with other Cu deposition methods, this CDT easily controls the interface of the Cu-insulator, the switching layer thickness, and the immunity of the Cu etching process, assisting the 1-transistor-1-ReRAM (1T-1R) structure and system-on-chip integration. The modulated shape of the Cu-SiO2 interface and the thickness of the SiO2 layer obtained by CDT-based Cu deposition on SiO2 were confirmed by scanning electron microscopy and atomic force microscopy. The CDT-fabricated Cu/SiO2-stacked ReRAM exhibited lower operation voltages and more stable data retention characteristics than the control Cu/SiO2-stacked sample. As the Cu CDT processing time increased, the forming and set voltages of the CDT-fabricated Cu/SiO2-stacked ReRAM decreased. Conversely, decreasing the processing time reduced the on-state current and reset voltage while increasing the endurance switching cycle time. Therefore, the switching characteristics were easily modulated by Cu CDT, yielding a high performance electrochemical metallization (ECM)-type ReRAM.
Robust Data Retention and Superior Endurance of Silicon-Oxide-Nitride-Oxide-Silicon-Type Nonvolatile Memory with NH3-Plasma-Treated and Pd-Nanocrystal-Embedded Charge Storage Layer
(2012-04-01)
Liu, Sheng-Hsien
;
Yang, Wen-Luh
;
Hsiao, Yu-Ping
;
Chao, Tien-Sheng
;
電子物理學系
In this study, we investigated an ammonia (NH3) plasma-pretreatment (PT) for suppressing the formation of interface states between metal nanocrystals (NCs) and the surrounding dielectric during the NC forming process with the aim of obtaining a highly reliable Pd NC memory. The discharge-based multipulse (DMP) technique was performed to analyze the distribution of trap energy levels in the Pd NCs/Si3N4-stacked storage layer. Through DMP analysis, it is confirmed that the NH3 PT not only significantly increases the quality of the surrounding dielectric of metal NCs but also effectively passivates shallow trap sites in the Si3N4 trapping layer. As compared with the sample without NH3 PT, the NH3-plasma-treated device exhibits better reliability characteristics such as excellent charge retention (only 5% charge loss for 10(4) s retention time) and very high endurance (no memory window narrowing after 10(5) program/erase cycles). In addition, the robust multilevel cell retention properties of the NH3-plasma-treated memory are also demonstrated. (C) 2012 The Japan Society of Applied Physics
Switching characteristics in Cu:SiO2 by chemical soak methods for resistive random access memory (ReRAM)
(2015-01-01)
Chin, Fun-Tat
;
Lin, Yu-Hsien
;
Yang, Wen-Luh
;
Liao, Chin-Hsuan
;
Lin, Li-Min
A limited copper (Cu)-source Cu:SiO2 switching layer composed of various Cu concentrations was fabricated using a chemical soaking (CS) technique. The switching layer was then studied for developing applications in resistive random access memory (ReRAM) devices. Observing the resistive switching mechanism exhibited by all the samples suggested that Cu conductive filaments formed and ruptured during the set/reset process. The experimental results indicated that the endurance property failure that occurred was related to the joule heating effect. Moreover, the endurance switching cycle increased as the Cu concentration decreased. In high-temperature tests, the samples demonstrated that the operating (set/reset) voltages decreased as the temperature increased, and an Arrhenius plot was used to calculate the activation energy of the set/reset process. In addition, the samples demonstrated stable data retention properties when baked at 85 degrees C, but the samples with low Cu concentrations exhibited short retention times in the low-resistance state (LRS) during 125 degrees C tests. Therefore, Cu concentration is a crucial factor in the trade-off between the endurance and retention properties; furthermore, the Cu concentration can be easily modulated using this CS technique. (C) 2014 Elsevier Ltd. All rights reserved.