Browsing by Author "Chin, Fun-Tat"

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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.
High Performance Cu-doped SiO2 ReRAM by a Novel Chemical Soak Method
(2011-01-01)
Chin, Fun-Tat
;
Yang, Wen-Luh
;
Chao, Tien-Sheng
;
Chang, Yuan-Ming
;
Lin, Li-Min
In this paper, a novel chemical soak method is proposed to fabricate a Cu-doped SiO2 ReRAM device. This method can easily fabricate a lightly Cu-doped SiO2 film and effectively improve the reliability of the conventional Cu-doped SiO2 ReRAM device. A reproducible bipolar switching characteristic with set/reset voltage (ca. 2.5 V/ -0.7 V) is performed in this device and the electrical conduction in HRS and LRS are related to Poole-Frenkel and Ohmic conduction, respectively. Excellent performance in terms of high on/off ratio (similar to 10(6)), narrow range distribution of set and reset voltages, stable data retention, and up to 110 times switching cycles has been achieved by this novel chemical soak method for Cu-doped SiO2 ReRAM device.
SONOS memories with embedded silicon nanocrystals in nitride by In-situ deposition method
(2008)
Wu, Yi-Hong
;
Chiang, Tsung-Yu
;
Liu, Sheng-Hsien
;
Yang, Wen-Luh
;
Chao, Tien-Sheng
In this work, we have successfully demonstrated SONOS memories with embedded Si-NCs in silicon nitride by In-situ deposition method. The self-assembly silicon nanocrystals were in-situ deposited within the Si3N4 storage layer by dissociation of dichlorosilane (SiH2Cl2) gas to a high density of 9 x 10(11) cm(-2). This new structure exhibits larger memory windows for up to 6 V, better program/erase characteristics, and excellent data retention properties as compared to control device. In addition, this novel process is simple, low cost, and compatible to the standard complementary metal-oxide-semiconductor (CMOS) processes. This technology seems to be very promising for the advanced flash memory devices.
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.