Browsing by Author "Chang, Yao-Feng"

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A study of resistive switching effects on a thin FeO(x) transition layer produced at the oxide/iron interface of TiN/SiO(2)/Fe-contented electrode structures
(2010-02-01)
Feng, Li-Wei
;
Chang, Chun-Yen
;
Chang, Yao-Feng
;
Chen, Wei-Ren
;
Wang, Shin-Yuan
Large (>10(2)) and stable resistance switching characteristics were demonstrated in TiN/SiO(2)/Fe structure due to the presence of a thin FeO(x) transition layer at the SiO(2)/Fe interface, produced spontaneously during the plasma-enhanced tetraethyl orthosilicate oxide deposition process. Addition of Pt into Fe electrode, i.e., a TiN/SiO(2)/Fe(0.73)Pt(0.27) structure, was observed to improve the data dispersion of switching parameters, associating with the decrease in Fe content inside the FeO(x) layer. Additionally, current-voltage fitting data shows that current transport mechanism is governed by Ohm's law in low voltage region and Pool-Frenkel behavior in high voltage region, consisting with FeO(x) phase transition characteristics.
A study of resistive switching effects on a thin FeOx transition layer produced at the oxide/iron interface of TiN/SiO2/Fe-contented electrode structures
(2010-02-01)
Feng, Li-Wei
;
Chang, Chun-Yen
;
Chang, Yao-Feng
;
Chen, Wei-Ren
;
Wang, Shin-Yuan
Large (>10(2)) and stable resistance switching characteristics were demonstrated in TiN/SiO2/Fe structure due to the presence of a thin FeOx transition layer at the SiO2/Fe interface, produced spontaneously during the plasma-enhanced tetraethyl orthosilicate oxide deposition process. Addition of Pt into Fe electrode, i.e., a TiN/SiO2/Fe0.73Pt0.27 structure, was observed to improve the data dispersion of switching parameters, associating with the decrease in Fe content inside the FeOx layer. Additionally, current-voltage fitting data shows that current transport mechanism is governed by Ohm's law in low voltage region and Pool-Frenkel behavior in high voltage region, consisting with FeOx phase transition characteristics.
A Study of the Relationship Between Endurance and Retention Reliability for a HfOx-Based Resistive Switching Memory
(2020-09-01)
Chung, Wei-Min
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Chang, Yao-Feng
;
Hsu, Yu-Lin
;
Chen, Y. -C. Daphne
;
Lin, Chao-Cheng
This study determines the relationship between retention and endurance reliability for a HfOx-based resistive random access memory (ReRAM). A TiN (15 nm) / HfOx (6 nm) / Ti (10 nm) / TiN (40 nm) stacked structure is fabricated and tested to verify its basic characteristics and reliability. The high resistance states (HRS) retention behavior is characterized and is found to degrade over 100x on the endured bits because there is a sequential high temperature procedure. The degradation is reduced slightly to a similar to 30x drop for the endured devices with one single refresh cycle. During the endurance and retention test procedures, the HRS resistance decreases because neutral oxygen vacancy filaments grow and this cannot be reversed. The I-V characteristics for endured devices are also determined. The results show that isothermal treatment causes a gradual SET and RESET process with multiple feasible states. The thermally induced filament degradation model (isolated filament vs. continuous filament) is verified by the relationship between retention and endurance reliability. Design guidance is recommended for an improvement in ReRAM reliability.
A Universal Model for Interface-type Threshold Switching Phenomena by Comprehensive Study of Vanadium Oxide-Based Selector
(2017-01-01)
Lin, Chih-Yang
;
Chen, Ying-Chen
;
Gu, Meiqi
;
Pan, Chih-Hung
;
Jin, Fu-Yuan
For the first time, a comprehensive study of Vanadium oxide-based selector characteristics with a universal model observed by thermal and electrical induced threshold switching (TS) phenomena at interface is presented in this work. The model can explain that the resistance evolution by thermal temperature in TS behaviors, as well as the resistance gradually increases with cycling ("seasoning effect"). Compatible current density (10(7)similar to 10(9) A/cm(2)) and selectivity (similar to 100) with physical understanding of evolution in energy barrier and MIT metallic state modulation are studied. The results show a promising design guideline for future storage-class memory (SCM) applications.
Attaining resistive switching characteristics and selector properties by varying forming polarities in a single HfO2-based RRAM device with a vanadium electrode
(2017-07-07)
Lin, Chih-Yang
;
Chen, Po-Hsun
;
Chang, Ting-Chang
;
Chang, Kuan-Chang
;
Zhang, Sheng-Dong
This study proposes a method for a HfO2-based device to exhibit both resistive switching (RS) characteristics as resistive random access memory (RRAM) and selector characteristics by introducing vanadium (V) as the top electrode. This simple V/HfO2/TiN structure can demonstrate these two different properties depending on forming polarities. The RS mechanism is activated by a positive forming bias. In contrast, the selector property is induced by a negative forming bias. The material analyses firstly confirm the existence of V in the top electrode. Then the electrical measurements for the same V/HfO2/TiN structures but with different forming polarities were carried out to further investigate their DC sweeping characteristics to act as either a selector or RRAM device. Furthermore, reliability tests for both selector and RRAM devices were also conducted to confirm their switching stabilities. Finally, current fitting methods and temperature influence experiments were performed to investigate the carrier transport mechanisms. Finally, physical models were proposed to illustrate the selector property and RS mechanism for selector and RRAM devices, respectively. This simple device structure with its easy operating method accomplishes a significant advancement of devices combining both selector properties and RRAM for remarkable real applications in the near future.
Charge Quantity Influence on Resistance Switching Characteristic During Forming Process
(2013-04-01)
Chu, Tian-Jian
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Wu, Hsing-Hua
;
Chen, Jung-Hui
In this letter, we presented that the charge quantity is the critical factor for forming process. Forming is a pivotal process in resistance random access memory to activate the resistance switching behavior. However, overforming would lead to device damage. In general, the overshoot current has been considered as a degradation reason during the forming process. In this letter, the quantity of charge through the switching layer has been proven as the key element in the formation of the conduction path. Ultrafast pulse forming can form a discontinuous conduction path to reduce the operation power.
Comprehensive Trap-Level Study in SiOx-based Resistive Switching Memory
(2013)
Chang, Yao-Feng
;
Chen, Ying-Chen
;
Li, Ji
;
Xue, Fei
;
Wang, Yanzhen
Five-element circuit model using linear-regression method to correct the admittance measurement of metal-oxide-semiconductor capacitor
(2009-01-01)
Cheng, Chao-Ching
;
Chien, Chao-Hsin
;
Luo, Guang-Li
;
Liu, Jun-Cheng
;
Chen, Yi-Cheng
The authors present a linear-regression method based on a five-element circuit model to correct measured capacitance-voltage and conductance-voltage curves. This model explains the effects of series resistance and parasitic capacitance/inductance on the frequency dispersion of measured capacitance and the magnification of measured conductance. These extracted parasitic components show significant dependencies on the geometry of capacitor structure, thereby causing different frequency-dependent capacitance characteristics in measurements. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3058724]
Improvement of resistance switching characteristics in a thin FeO(x) transition layer of TiN/SiO(2)/FeO(x)/FePt structure by rapid annealing
(2010-05-31)
Feng, Li-Wei
;
Chang, Chun-Yen
;
Chang, Yao-Feng
;
Chang, Ting-Chang
;
Wang, Shin-Yuan
In this paper, the influence of a 600 degrees C rapid thermal annealing for 60 s on the improvements of resistance switching behaviors in a TiN/SiO(2)/FeO(x)/FePt structure is reported. It is found that besides the distinct reduction in memory switching parameters in forming voltage, set/reset voltages, and their dispersions, the resistance ratio of high-resistance state to low-resistance state is also enlarged after annealing. The effects of annealing on improving the resistance switching properties are discussed by x-ray diffraction and x-ray photon-emission spectra depth profile results. Additionally, good retention characteristics are exhibited in the annealed TiN/SiO(2)/FeO(x)/FePt resistance switching memory. (C) 2010 American Institute of Physics. [doi:10.1063/1.3428777]
Improvement of resistance switching characteristics in a thin FeOx transition layer of TiN/SiO2/FeOx/FePt structure by rapid annealing
(2010-05-31)
Feng, Li-Wei
;
Chang, Chun-Yen
;
Chang, Yao-Feng
;
Chang, Ting-Chang
;
Wang, Shin-Yuan
In this paper, the influence of a 600 degrees C rapid thermal annealing for 60 s on the improvements of resistance switching behaviors in a TiN/SiO2/FeOx/FePt structure is reported. It is found that besides the distinct reduction in memory switching parameters in forming voltage, set/reset voltages, and their dispersions, the resistance ratio of high-resistance state to low-resistance state is also enlarged after annealing. The effects of annealing on improving the resistance switching properties are discussed by x-ray diffraction and x-ray photon-emission spectra depth profile results. Additionally, good retention characteristics are exhibited in the annealed TiN/SiO2/FeOx/FePt resistance switching memory. (C) 2010 American Institute of Physics. [doi:10.1063/1.3428777]
Integrated One Diode-One Resistor Architecture in Nanopillar SiOx Resistive Switching Memory by Nanosphere Lithography
(2014-02-01)
Ji, Li
;
Chang, Yao-Feng
;
Fowler, Burt
;
Chen, Ying-Chen
;
Tsai, Tsung-Ming
We report on a highly compact, one diode-one resistor (1D-1R) nanopillar device architecture for SiOx-based ReRAM fabricated using nanosphere lithography (NSL). The intrinsic SiOx-based resistive switching element and Si diode are self-aligned on an epitaxial silicon wafer using NSL and a deep-Si-etch process without conventional photolithography. AC-pulse response in 50 ns regime, multibit operation, and good reliability are demonstrated. The NSL process provides a fast and economical approach to large-scale patterning of high-density 1D-1R ReRAM with good potential for use in future applications.
Investigation statistics of bipolar multilevel memristive mechanism and characterizations in a thin FeO(x) transition layer of TiN/SiO(2)/FeO(x)/Fe structure
(2011-09-01)
Chang, Yao-Feng
;
Chang, Ting-Chang
;
Chang, Chun-Yen
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We investigated multilevel resistance switching characteristics of the thin FeO(x) transition layer in a TiN/SiO(2)/FeO(x)/Fe structure by controlling the current compliance and stopped voltage during the set and reset processes, respectively. It is observed that the resistive state could be easily tunable by controlling external electric conditions. The multilevel memristive mechanism was characterized by distinguishing the electrical behaviors statistically, inferring that the reset process is associated with the mobile-ion-assisted electrochemical redox. Moreover, the set process is also modeled by power dissipation behaviors. The presented mathematical and physical model provides a possibility to elucidate a universal mechanism for bipolar multilevel memristor. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3630119]
Investigation statistics of bipolar multilevel memristive mechanism and characterizations in a thin FeO(x) transition layer of TiN/SiO(2)/FeO(x)/Fe structure (vol 110, 053703, 2011)
(2011-12-01)
Chang, Yao-Feng
;
Chang, Ting-Chang
;
Chang, Chun-Yen
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Investigation statistics of bipolar multilevel memristive mechanism and characterizations in a thin FeOx transition layer of TiN/SiO2/FeOx/Fe structure (vol 110, 053703, 2011)
(2011-12-01)
Chang, Yao-Feng
;
Chang, Ting-Chang
;
Chang, Chun-Yen
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Mechanism and characterizations studies of resistive switching effects on a thin FeO(x)-transition layer of the Ti/TiN/SiO(2)/FeO(x)/FePt structure by thermal annealing treatments
(2011-12-15)
Chang, Yao-Feng
;
Feng, Li-Wei
;
Chang, Ting-Chang
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We investigated annealing effects on the bipolar resistive switching characteristics and mechanism of the thin FeO(x) transition layer in a Ti/TiN/SiO(2)/FeO(x)/FePt structure by depositing a plasma-enhanced tetraethyl orthosilicate oxide onto the Fe-contented electrode. The electrical results show that the values of operation voltage, variation of electrical parameters and retention properties could be improved with the increasing thermal treatment budget. Tunneling electron microscope, X-ray diffraction, Auger electron spectroscopy and X-ray photon-emission spectra depth profiles were examined for cross-section image, crystallinity and composition analyses of the transition layer. In order to investigate the resistive switching mechanism and characterizations in Ti/TiN/SiO(2)/FeO(x)/FePt structure, the electrical parameters were extracted during set and reset process. The retention property at room temperature and 85 C was improved after the thermal treatment and maintains both resistance states over 6 x 10(4) s implies promising potential for future memory application. (C) 2011 Elsevier B.V. All rights reserved.
Mechanism and characterizations studies of resistive switching effects on a thin FeOx-transition layer of the Ti/TiN/SiO2/FeOx/FePt structure by thermal annealing treatments
(2011-12-15)
Chang, Yao-Feng
;
Feng, Li-Wei
;
Chang, Ting-Chang
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We investigated annealing effects on the bipolar resistive switching characteristics and mechanism of the thin FeOx transition layer in a Ti/TiN/SiO2/FeOx/FePt structure by depositing a plasma-enhanced tetraethyl orthosilicate oxide onto the Fe-contented electrode. The electrical results show that the values of operation voltage, variation of electrical parameters and retention properties could be improved with the increasing thermal treatment budget. Tunneling electron microscope, X-ray diffraction, Auger electron spectroscopy and X-ray photon-emission spectra depth profiles were examined for cross-section image, crystallinity and composition analyses of the transition layer. In order to investigate the resistive switching mechanism and characterizations in Ti/TiN/SiO2/FeOx/FePt structure, the electrical parameters were extracted during set and reset process. The retention property at room temperature and 85 C was improved after the thermal treatment and maintains both resistance states over 6 x 10(4) s implies promising potential for future memory application. (C) 2011 Elsevier B.V. All rights reserved.
Reproducible resistance switching of a relatively thin FeO(x) layer produced by oxidizing the surface of a FePt electrode in a metal-oxide-metal structure
(2010-12-30)
Feng, Li-Wei
;
Chang, Yao-Feng
;
Chang, Chun-Yen
;
Chang, Ting-Chang
;
Wang, Shin-Yuan
In this study, reproducible resistance switching effects were demonstrated on a relatively thin FeO(x) layer in the TiN/SiO(2)/FeO(x)/FePt structure produced by oxidizing the surface of a FePt electrode during a plasma-enhanced tetraethyl orthosilicate oxide deposition process. Characteristics of the non-stoichiometric FeO(x) transition layer were examined by Auger electron spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy analyses. In addition, characteristics of the forming process as well as the current transport characteristics after forming process in the TiN/SiO(2)/FeO(x)/FePt structure were discussed. Moreover, the role of the silicon oxide layer was also experimentally demonstrated to act as an additional supplier of oxygen ions for the switching requirement by biasing high voltage bias conditions. (C) 2010 Elsevier B.V. All rights reserved.
Reproducible resistance switching of a relatively thin FeOx layer produced by oxidizing the surface of a FePt electrode in a metal-oxide-metal structure
(2010-12-30)
Feng, Li-Wei
;
Chang, Yao-Feng
;
Chang, Chun-Yen
;
Chang, Ting-Chang
;
Wang, Shin-Yuan
In this study, reproducible resistance switching effects were demonstrated on a relatively thin FeOx layer in the TiN/SiO2/FeOx/FePt structure produced by oxidizing the surface of a FePt electrode during a plasma-enhanced tetraethyl orthosilicate oxide deposition process. Characteristics of the non-stoichiometric FeOx transition layer were examined by Auger electron spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy analyses. In addition, characteristics of the forming process as well as the current transport characteristics after forming process in the TiN/SiO2/FeOx/FePt structure were discussed. Moreover, the role of the silicon oxide layer was also experimentally demonstrated to act as an additional supplier of oxygen ions for the switching requirement by biasing high voltage bias conditions. (C) 2010 Elsevier B.V. All rights reserved.
Resistive Switching of SiOX with One Diode-One Resistor Nanopillar Architecture Fabricated via Nanosphere Lithography
(2014)
Ji, Li
;
Chang, Yao-Feng
;
Fowler, Burt
;
Chen, Ying-Chen
;
Tsai, Tsung-Ming
Role of germanium in the reduced temperature dependence of Ti-based nanocrystals formation for nonvolatile memory applications
(2009-12-28)
Feng, Li-Wei
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Chang, Chun-Yen
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Chang, Ting-Chang
;
Tu, Chun-Hao
;
Wang, Pai-Syuan
We investigated the physical and electrical characteristics of Ti-based nanocrystals (NCs) with composition of germanium fabricated by cosputtering titanium silicide and germanium targets for low temperature applications of nonvolatile memory. The addition of Ge significantly reduces the thermal budget necessary for Ti-based NCs formation to 500 degrees C in 2 min due to the rise of its morphological instability and agglomeration properties. Compositions characteristics were analyzed by x-ray photon-emission spectroscopy and formations of NCs were observed by transmission electron microscopy. Additionally, capacitance-voltage characteristics, data retention, and endurance properties are characterized to demonstrate its advantages for nonvolatile memory device applications.