Browsing by Author "Huang, Sheng-Yao"

Now showing 1 - 11 of 11

A low-temperature method for improving the performance of sputter-deposited ZnO thin-film transistors with supercritical fluid
(2009-04-20)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Huang, Sheng-Yao
;
Chang, Kuan-Chang
;
Li, Hung-Wei
A low-temperature method, supercritical CO(2) (SCCO(2)) fluid technology, is employed to improve the device properties of ZnO TFT at 150 degrees C. In this work, the undoped ZnO films were deposited by sputter at room temperature and treated by SCCO(2) fluid which is mixed with 5 ml pure H(2)O. After SCCO(2) treatment, the on/off current ratios and threshold voltage of the device were improved significantly. From x-ray photoelectron spectroscopy analyses, the enhancements were attributed to the stronger Zn-O bonds, the hydrogen-related donors, and the reduction in dangling bonds at the grain boundary by OH passivation.
Bipolar Resistive Switching Characteristics of Transparent Indium Gallium Zinc Oxide Resistive Random Access Memory
(2010)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Huang, Sheng-Yao
;
Chen, Shih-Ching
;
Hu, Chih-Wei
This study investigates a sputtered InGaZnO (IGZO) thin film to apply into a resistive random access memory device. After the formation of an indium tin oxide (ITO)/IGZO/ITO structure at room temperature, the device exhibits a repeatable bipolar resistance switching behavior without an electroforming process and an excellent transmittance in the visible region. The conduction mechanisms for low and high resistance states are dominated by Ohm's law and space-charge-limited current behavior, respectively. In retention and endurance tests, a resistance ratio of more than 1 order remains after 10(4) s at 90 degrees C and after 100 dc voltage sweeping cycles. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3360181] All rights reserved.
Effect of Electrode Material on Resistive Switching Characteristics in TaON Nonvolatile Memory Devices
(2013-01-01)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Chiu, Yi-Chieh
;
Chen, Shih-Cheng
;
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.
Improvement in the bias stability of amorphous InGaZnO TFTs using an Al2O3 passivation layer
(2013-09-01)
Huang, Sheng-Yao
;
Chang, Ting-Chang
;
Chen, Min-Chen
;
Chen, Te-Chih
;
Jian, Fu-Yen
This work presents the light-color-dependent negative bias stress (NBIS) effect on amorphous indium gallium zinc oxide (a-IGZO) thin film transistors (TFTs) with Al2O3 passivation layer. The colors of incident photon are varied from red to blue, that incident photon energies are all lower than the optical band gap of IGZO (3.2 eV). The experimental results show that the Al2O3 passivated devices present stable electrical behaviors under different incident lights (Delta V-T<0.1 V of dark and red, Delta V-T<1 V of green, and Delta V-T<4 V of blue), whereas the unpassivation devices exhibit observable negative shifts during NBIS (Delta V-T<1 V of dark and red, Delta V-T>8 V of green, and Delta V-T>15 V of blue). The degradation mechanism of the negative bias stress under illumination of a-IGZO TFTs is dominated by the photo-generated hole trapping at the gate insulator and/or interface between insulator and channel. In this result, the Al2O3 passivation layer can effectively passivate the defect in the a-IGZO film, reducing electron hole pair generated during the illumination processed. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
Improvement of the performance of ZnO TFTs by low-temperature supercritical fluid technology treatment
(2009-12-25)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Huang, Sheng-Yao
;
Chang, Kuan-Chang
;
Huang, Hui-Chun
in this paper, the supercritical CO(2) (SCCO(2)) fluid technology is successfully applied to improve the electrical characteristics of sputtered ZnO TFTs at low temperature (150 degrees C). After the treatment of SCCO(2) fluids mixed with water, the ZnO TFT exhibited superior transfer characteristics and lower threshold voltage. According to X-ray photoelectron spectroscopy (XPS) analyses, the improvements were attributed to the increase of binding energies of Zn-O bonds, hydrogen-related donors and the reduction of traps at the grain boundaries in ZnO thin films. In addition, the crystalline quality and microstructure of ZnO thin films were also investigated by using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The transmittance of the ZnO film was measured by an N&K analyzer 1280 (N&K Technology, Inc.), which is a new type of thin-film measurement system. (C) 2009 Elsevier B.V. All rights reserved.
Influence of electrode material on the resistive memory switching property of indium gallium zinc oxide thin films
(2010-06-28)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Tsai, Chih-Tsung
;
Huang, Sheng-Yao
;
Chen, Shih-Ching
The InGaZnO taken as switching layer in resistive nonvolatile memory is proposed in this paper. The memory cells composed of Ti/InGaZnO/TiN reveal the bipolar switching behavior that keeps stable resistance ratio of 10(2) with switching responses over 100 cycles. The resistance switching is ascribed to the formation/disruption of conducting filaments upon electrochemical reaction near/at the bias-applied electrode. The influence of electrode material on resistance switching is investigated through Pt/InGaZnO/TiN devices, which perform the unipolar and bipolar behavior as applying bias on Pt and TiN electrode, respectively. Experimental results demonstrate that the switching behavior is selective by the electrode. (C) 2010 American Institute of Physics. [doi:10.1063/1.3456379]
Influence of Oxygen Partial Pressure on Resistance Random Access Memory Characteristics of Indium Gallium Zinc Oxide
(2011)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Huang, Sheng-Yao
;
Chang, Guan-Chang
;
Chen, Shih-Cheng
This paper investigates the effect of oxygen concentrations of InGaZnO films on the resistive switching characteristics of a Pt/InGaZnO (IGZO)/TiN structure. The IGZO films were prepared by an RF magnetron sputtering system at various oxygen partial pressures at room temperature. The memory devices reveal a reversible unipolar switching behavior. In addition, the high-resistance state current was found to be strongly dependent on oxygen concentration. X-ray photoelectron spectroscopy analyses attributed this phenomenon to the non-lattice oxygen concentration in the IGZO thin films, rather than the change in crystalline constituent. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.007112esl] All rights reserved.
Investigating the degradation behavior caused by charge trapping effect under DC and AC gate-bias stress for InGaZnO thin film transistor
(2011-07-11)
Chen, Te-Chih
;
Chang, Ting-Chang
;
Hsieh, Tien-Yu
;
Lu, Wei-Siang
;
Jian, Fu-Yen
This letter investigates the degradation mechanism of amorphous indium-gallium-zinc oxide thin-film transistors under gate-bias stress. The larger V(t) shift under positive AC gate-bias stress when compared to DC operation indicates that an extra electron trapping mechanism occurs during rising/falling time during the AC pulse period. In contrast, the degradation behavior under illuminated negative gate-bias stress exhibits the opposite degradation tendency. Since electron and hole trapping are the dominant degradation mechanisms under positive and illuminated negative gate-bias stress, respectively, the different degradation tendencies under AC/DC operation can be attributed to the different trapping efficiency of electrons and holes. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3609873]
Resistive switching characteristics of Sm(2)O(3) thin films for nonvolatile memory applications
(2011-09-01)
Huang, Sheng-Yao
;
Chang, Ting-Chang
;
Chen, Min-Chen
;
Chen, Shih-Ching
;
Lo, Hung-Ping
This study investigates a sputtered Sm(2)O(3) thin film to apply into a resistive random access memory device. The proposed device exhibits a stable resistance ratio of about 2.5 orders after 10(4) cycling bias pulses and no degradation for retention characteristics monitored after an endurance test at 85 degrees C. The conduction mechanisms for low and high resistance states are dominated by ohmic behavior and trapcontrolled space charge limited current, respectively. The resistance switching is ascribed to the formation/rupture of conductive filaments. (C) 2011 Elsevier Ltd. All rights reserved.
Resistive switching characteristics of Sm2O3 thin films for nonvolatile memory applications
(2011-09-01)
Huang, Sheng-Yao
;
Chang, Ting-Chang
;
Chen, Min-Chen
;
Chen, Shih-Ching
;
Lo, Hung-Ping
This study investigates a sputtered Sm2O3 thin film to apply into a resistive random access memory device. The proposed device exhibits a stable resistance ratio of about 2.5 orders after 10(4) cycling bias pulses and no degradation for retention characteristics monitored after an endurance test at 85 degrees C. The conduction mechanisms for low and high resistance states are dominated by ohmic behavior and trapcontrolled space charge limited current, respectively. The resistance switching is ascribed to the formation/rupture of conductive filaments. (C) 2011 Elsevier Ltd. All rights reserved.
The resistive switching characteristics in TaON films for nonvolatile memory applications
(2013-01-15)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Chiu, Yi-Chieh
;
Chen, Shih-Cheng
;
Huang, Sheng-Yao
In this study, the bipolar resistive switching characteristics of the resistive random access memory (RRAM) device based on sputter-deposited TaON thin film were investigated. The proposed memory device exhibits excellent resistance switching behavior with a high resistance state to low resistance state ratio of 2.5 order, write/erase endurance of about 1.5 order, and long retention time of 10(4) s at 85 degrees C. In addition, the device was investigated to achieve multilevel operation, which could increase storage density for next generation memory application. It was also found that the polarity of the forming process would not influence the resistive switching characteristic but would affect the first reset process behavior. The switching behavior could be regarded as the oxygen redox near the TiN interface. However, the first reset behavior of negative forming process was related to the oxygen concentration gradients near the Pt electrode and the Joule heating enhanced oxidation. (c) 2012 Elsevier B.V. All rights reserved.