Browsing by Author "Syu, Yong-En"

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A Method to Determine the Located Region of Lateral Trap Position by Analysis of Three-Level Random Telegraph Signals in n-MOSFETs
(2015-01-01)
Chen, Ching-En
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Chang, Ting-Chang
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You, Bo
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Tsai, Jyun-Yu
;
Lo, Wen-Hung
This paper introduces a method to determine the located region of trap position by the analysis of three-level random telegraph signal (RTS) in partially-depleted silicon-on-insulator n-channel metal-oxide-semiconductor field-effect-transistors. For the cases of two traps, the average time at the 2nd level ((12)) is composed of average emission time of one trap and average capture time of the other. Comparison and analysis of (tau(2)) curves varying with gate voltage in RTS measurements with and without interchanged source/drain can clarify the located regions of the two traps. Moreover, the simplified equations are also considered and used to confirm the trap positions. (C) 2015 The Electrochemical Society. All rights reserved.
Abnormal Subthreshold Leakage Current at High Temperature in InGaZnO Thin-Film Transistors
(2012-04-01)
Chang, Geng-Wei
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Chang, Ting-Chang
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Jhu, Jhe-Ciou
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Tsai, Tsung-Ming
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Syu, Yong-En
Abnormal subthreshold leakage current is observed at high temperature in amorphous InGaZnO thin-film transistors. The transfer curve exhibits an apparent subthreshold current stretch-out phenomenon that becomes more serious with increasing temperatures. The negative bias temperature instability experiment has been used to prove high-temperature-induced hole generation. Furthermore, the transfer characteristics with different drain voltages have been also used to confirm the status of hole accumulation. These pieces of evidence clearly defined the stretch-out phenomenon, which is caused by thermal-induced hole generation and accumulation at the source region that leads to source-side barrier lowering.
Asymmetric Carrier Conduction Mechanism by Tip Electric Field in WSiOX Resistance Switching Device
(2012-03-01)
Syu, Yong-En
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Chang, Geng-Wei
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Chang, Kuan-Chang
Resistance random access memory (RRAM) is a great potential candidate for next-generation nonvolatile memory due to the outstanding memory characteristic. However, the resistance switching mechanism is still a riddle nowadays. In this letter, the switching mechanism is investigated by current-voltage (I-V) curve fitting in the TiN/WSiOX/Pt RRAM device. The asymmetric phenomenon of the carrier conduction behavior is explained at the high-resistance state in high electric field. The switching behavior is regarded to tip electric field by localizing the filament between the interface of top electrode and insulator.
Atomic-level quantized reaction of HfOx memristor
(2013-04-29)
Syu, Yong-En
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Chang, Ting-Chang
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Lou, Jyun-Hao
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Tsai, Tsung-Ming
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Chang, Kuan-Chang
In this study, we have observed dynamic switching behaviors in a memristive device. There are only a few atoms in the resistive switching reaction which enables the high-speed resistive switching characteristics, which was analyzed dynamically by real-time analyzing tools. From fundamental conductance considerations, the resistance of the conductive path in HfOx memristor is found to be due to barriers which are atomically incremented during the RESET process. Simultaneously, we have demonstrated the quantized switching phenomena at ultra-cryogenic temperature (4 K), which are attributed to the atomic-level reaction in metallic filament. (C) 2013 AIP Publishing LLC.
Bipolar Resistive RAM Characteristics Induced by Nickel Incorporated Into Silicon Oxide Dielectrics for IC Applications
(2012-12-01)
Tsai, Tsung-Ming
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Syu, Yong-En
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Chuang, Siang-Lan
In this letter, we successfully produced resistive switching behaviors by nickel doped into silicon oxide at room temperature. The nickel element was doped into silicon oxide, which is a useful dielectric material in integrated circuit (IC) industries by cosputtering technology. Based on the proposed method, satisfactory reliability of the resistance switching device can be demonstrated by endurance and retention evaluation. We believe that the silicon oxide doped with nickel at room temperature is a promising method for resistive random access memory nonvolatile memory applications due to its compatibility with the IC processes.
Characteristics and Mechanisms of Silicon-Oxide-Based Resistance Random Access Memory
(2013-03-01)
Chang, Kuan-Chang
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Tsai, Tsung-Ming
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Chang, Ting-Chang
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Wu, Hsing-Hua
;
Chen, Jung-Hui
Traditionally, a large number of silicon oxide materials are extensively used as various dielectrics for semiconductor industries. In general, silicon oxide cannot be used as resistance random access memory (RRAM) due to its insulating electrical properties. In this letter, we have successfully produced resistive switching and forming-free behaviors by zinc doped into silicon oxide. The current-voltage fitting data show that current transport mechanism is governed by Poole-Frenkel behavior in high-resistance state and Ohm's law in low-resistance state, consisting with filament theory. Additionally, good endurance and retention reliabilities are exhibited in the zinc-doped silicon oxide RRAM.
Characteristics of hafnium oxide resistance random access memory with different setting compliance current
(2013-10-14)
Su, Yu-Ting
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Zhang, Rui
In this Letter, the characteristics of set process of hafnium oxide based resistance random access memory are investigated by different set processes with increasing compliance current. Through current fitting, carrier conduction mechanism of low resistance state changes from hopping to surface scattering and finally to ohmic conduction with the increase of setting compliance current. Experimental data of current-voltage measurement under successive increasing temperature confirms the conduction mechanism transition. A model of filament growth is eventually proposed in a way by merging discrete metal precipitates and electrical field simulation by COMSOL Multiphysics further clarifies the properties of filament growth process. (C) 2013 AIP Publishing LLC.
Characterization of Oxygen Accumulation in Indium-Tin-Oxide for Resistance Random Access Memory
(2014-06-01)
Zhang, Rui
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Huang, Syuan-Yong
In this letter, we report the oxygen accumulation effect and its influence on resistive switching for gadolinium-doped silicon dioxide (Gd:SiO2) resistance random access memory (RRAM). We find that oxygen absorbance by indium-tin-oxide electrode affects the conduction current mechanism, and remarkably modifies the device performance of RRAM devices. By current fitting, Schottky emission can be observed in both low and high resistance states, from which conduction model is proposed to clarify the oxygen accumulation phenomenon. Reliability tests, including endurance and high temperature retention are further carried out, evaluating the significance of oxygen accumulation effect in redox reaction for RRAM devices.
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
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Wu, Hsing-Hua
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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.
Dehydroxyl effect of Sn-doped silicon oxide resistance random access memory with supercritical CO2 fluid treatment
(2012-09-10)
Tsai, Tsung-Ming
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Syu, Yong-En
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Liao, Kuo-Hsiao
The tin-doped can supply conduction path to induce resistance switching behavior. However, the defect of tin-doped silicon oxide (Sn:SiOx) increased the extra leakage path lead to power consumption and joule heating degradation. In the study, supercritical CO2 fluids treatment was used to improve resistive switching property. The current conduction of high resistant state in post-treated Sn:SiOx film was transferred to Schottky emission from Frenkel-Poole due to the passivation effect. The molecular reaction model is proposed that the defect was passivated through dehydroxyl effect of supercritical fluid technology, verified by material analyses of x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4750235]
Effect of different constant compliance current for hopping conduction distance properties of the Sn:SiOx thin film RRAM devices
(2016-03)
Chen, Kai-Huang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Liao, Kuo-Hsiao
To effectively lower the power consumption effect of Sn:SiO2 RRAM devices, the electrical hopping conduction mechanism for set/reset state was effectively used and achieved by different constant compliance current forming process. To assume and discuss the tin metal clustered reaction and electron transport behaviors in metallic filament path-forming model, the various electrical switching current and conduction mechanism model of the Sn:SiO2 RRAM devices for different constant compliance current were also investigated and described. Finally, the switching current relationship between hopping conduction energy and average inter-trap distance properties of the RRAM devices was also simulated and demonstrated in this study.
Effect of Electrode Material on Resistive Switching Characteristics in TaON Nonvolatile Memory Devices
(2013-01-01)
Chen, Min-Chen
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Chang, Ting-Chang
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Chiu, Yi-Chieh
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Chen, Shih-Cheng
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Huang, Sheng-Yao
The devices composed of Pt/TaON/TiN reveal bipolar switching behavior that shows excellent resistance ratio of 10(2) with operations over 100 DC cycles. The formation/disruption of conducting filaments by oxygen anions migration near/at the TiN electrode was applied to explain the switching behavior. In comparison with Pt/TaON/TiN device, the Cu/TaON/TiN device exhibits reversed bipolar resistive switching characteristic. The switching mechanism of Cu/TaON/TiN device is regarded as the Cu redox reaction and migration in the TaON film. Furthermore, the setting voltage of the Cu/TaON/TiN device is lower than that of the Pt/TaON/TiN device due to the confined conduction path by Cu filaments.
Effects of Varied Negative Stop Voltages on Current Self-Compliance in Indium Tin Oxide Resistance Random Access Memory
(2015-06-01)
Lin, Chih-Yang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Pan, Chih-Hung
We have previously investigated the automatic current compliance property for indium tin oxide (ITO) resistance random access memory (RRAM). Traditionally, for the purpose of protecting RRAM, it is necessary to set equipment current compliance during the set and forming processes of RRAM devices. ITO RRAM devices, however, have an intrinsic capability to limit their current. This letter examines this ITO RRAM current compliance in depth by applying a varied stop-voltage measurement method, where different negative stop voltages were adopted to manipulate oxygen ions. Combined with material analysis and conduction current fitting, a model was established.
Electrical conduction mechanism of Zn:SiOx resistance random access memory with supercritical CO2 fluid process
(2013-08-19)
Chang, Kuan-Chang
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Tsai, Tsung-Ming
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Zhang, Rui
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Chang, Ting-Chang
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Chen, Kai-Huang
In this study, the electrical conduction mechanism of Zn:SiOx resistance random access memory (RRAM) treated with supercritical CO2 fluid (SCCO2) process was investigated by low temperature measurement. The current of low resistance state for current-voltage curves in SCCO2-treated and untreated Zn:SiOx RRAM were measured and compared under a low temperature range from 100K to 298 K. The electrical conduction mechanisms of hopping conduction and metal-like behaviors in SCCO2-treated and untreated Zn:SiOx RRAM were discussed, respectively. Finally, the electrical conduction mechanism was analyzed and verified by the chemical composition and bonding intensity of XPS analyses. (C) 2013 AIP Publishing LLC.
Endurance Improvement Technology With Nitrogen Implanted in the Interface of WSiOx Resistance Switching Device
(2013-07-01)
Syu, Yong-En
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Zhang, Rui
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Chang, Kuan-Chang
Incorporation of nitrogen as an oxygen-confining layer in the resistance switching reaction region is investigated to improve the reliability of resistance random access memory (RRAM). The switching mechanism can be attributed to the formation and rupture of conduction filaments. A compatible WSiON (around 5 nm) layer is introduced at the interface of tungsten silicon oxide (WSiOx) and TiN electrode to prevent the randomly diffusing oxygen ions surpassing the storage region of the WSiON layer. The double-layer WSiOx/WSiON memory structure would enhance the endurance over 100 times so as to better confirm the WSiOx RRAM application of nonvolatile memory.
High performance of graphene oxide-doped silicon oxide-based resistance random access memory
(2013-11-21)
Zhang, Rui
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Chen, Kai-Huang
In this letter, a double active layer (Zr:SiO (x) /C:SiO (x) ) resistive switching memory device with outstanding performance is presented. Through current fitting, hopping conduction mechanism is found in both high-resistance state (HRS) and low-resistance state (LRS) of double active layer RRAM devices. By analyzing Raman and FTIR spectra, we observed that graphene oxide exists in C:SiO (x) layer. Compared with single Zr:SiO (x) layer structure, Zr:SiO (x) /C:SiO (x) structure has superior performance, including low operating current, improved uniformity in both set and reset processes, and satisfactory endurance characteristics, all of which are attributed to the double-layer structure and the existence of graphene oxide flakes formed by the sputter process.
Hopping conduction distance dependent activation energy characteristics of Zn:SiO2 resistance random access memory devices
(2013-04-01)
Chen, Kai-Huang
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Zhang, Rui
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Chang, Kuan-Chang
In this study, the hopping conduction distance variation of Zn:SiO2 resistance random access memory (RRAM) devices with different operating compliance currents was discussed and verified. To investigate and determine the hopping conduction distance dependent activation energy characteristics, the Arrhenius plot of low resistance state of Zn:SiO2 RRAM devices was applied, from which we proposed carrier conduction model. With the increase of current compliance, more metal ions would accumulate to form precipitates with larger diameter, which in turn resulted in the shortening of hopping distance. Because of shorter hopping distance, activation energy for carrier hopping would decrease. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4799655]
Hopping conduction properties of the Sn:SiO (X) thin-film resistance random access memory devices induced by rapid temperature annealing procedure
(2015-06-01)
Chen, Kai-Huang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Liao, Kuo-Hsiao
Bipolar switching properties and electrical conduction mechanism in Sn:SiO (X) thin-film RRAM devices were investigated and discussed. To complete the resistive switching properties of the stannum doped into silicon oxide thin films, the RTA-treated Sn:SiO (X) thin-film RRAM devices were investigated and discussed. In addition, the improvement qualities and electrical switching properties of the RTA-treated Sn:SiO (X) thin-film RRAM devices were carried out XPS, FT-IR, and IV measurement. The ohmic conduction with metal-like behavior and hopping conduction dependent activation energy properties by the Arrhenius plot equation in LRS of the Sn:SiO (X) thin films was investigated. The activation energy and hopping distance for the RTA-treated thin films were found to be 0.018 eV and 1.1 nm, respectively. For the compatibility with the IC processes, the RTA treatment was a promising method for the Sn:SiO (X) thin-film RRAM nonvolatile memory applications.
Hopping Effect of Hydrogen-Doped Silicon Oxide Insert RRAM by Supercritical CO2 Fluid Treatment
(2013-05-01)
Chang, Kuan-Chang
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Pan, Chih-Hung
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Chang, Ting-Chang
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Tsai, Tsung-Ming
;
Zhang, Rui
In this letter, we introduced hydrogen ions into titanium metal doped into SiO2 thin film as the insulator of resistive random access memory (RRAM) by supercritical carbon dioxide (SCCO)(2) fluid treatment. After treatment, low resistance state split in to two states, we find the insert RRAM, which means it has an operating polarity opposite from normal RRAM. The difference of the insert RRAM is owing to the resistive switching dominated by hydrogen ions, dissociated from OH bond, which was not by oxygen ions as usual. The current conduction mechanism of insert RRAM was hopping conduction due to the metal titanium reduction reaction through SCCO2.
Illumination Effect on Bipolar Switching Properties of Gd:SiO2 RRAM Devices Using Transparent Indium Tin Oxide Electrode
(2016-04-27)
Chen, Kai-Huang
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Chang, Kuan-Chang
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Chang, Ting-Chang
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Tsai, Tsung-Ming
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Liang, Shu-Ping
To discuss the optoelectronic effect on resistive random access memory (RRAM) devices, the bipolar switching properties and electron-hole pair generation behavior in the transparent indium tin oxide (ITO) electrode of Gd:SiO2 thin films under the ultraviolet (lambda = 400 nm) and red-light (lambda = 770 nm) illumination for high resistance state (HRS)/low resistance state (LRS) was observed and investigated. In dark environment, the Gd:SiO2 RRAM devices exhibited the ohmic conduction mechanism for LRS, exhibited the Schottky emission conduction and Poole-Frankel conduction mechanism for HRS. For light illumination effect, the operation current of the Gd:SiO2 RRAM devices for HRS/LRS was slightly increased. Finally, the electron-hole pair transport mechanism, switching conduction diagram, and energy band of the RRAM devices will be clearly demonstrated and explained.