Browsing by Author "Zhong, Chia-Wen"

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Effect of ITO electrode with different oxygen contents on the electrical characteristics of HfOx RRAM devices
(2013-09-01)
Zhong, Chia-Wen
;
Tzeng, Wen-Hsien
;
Liu, Kou-Chen
;
Lin, Horng-Chih
;
Chang, Kow-Ming
In this study, the influence of indium tin oxide (ITO) top electrodes with different oxygen contents on the resistive switching characteristics of HfOx/TiN capacitor structure is investigated. Switching parameters, including set and reset voltage values, and high and low resistance values are highly related to the properties of ITO thin films. Higher resistance values in both states can be obtained when ITO thin films with higher oxygen contents are used as top electrodes; such values are accompanied by larger set voltages and fluctuating transient currents during the reset process. Based on the proposed filament model, we suggest that the switching mechanism of HfOx/TiN structure is attributed to the formation and rupture of conducting filamentary paths near the anodic side, which is highly correlated with the properties of the top electrode. The top electrode must be well determined to obtain reliable switching properties. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
Impact of gate dielectrics and oxygen annealing on tin-oxide thin-film transistors
(2016-04)
Zhong, Chia-Wen
;
Lin, Horng-Chih
;
Tsai, Jung-Ruey
;
Liu, Kou-Chen
;
Huang, Tiao-Yuan
In this work, we study the impact of gate dielectrics on the characteristics of bottom-gated tin-oxide thin-film transistors annealed in an oxygen ambience at 300 degrees C for various periods. SiO2, HfO2, and Al2O3 are employed as the gate dielectric in the test devices. The results show that the devices will start exhibiting p-type conduction behavior as the annealing reaches a specific time period which is closely related to the underlying gate dielectric, and the device characteristics can be improved as the annealing proceeds further. Nonetheless, a prolonged annealing may cause degradation of the devices. High hole mobility (3.33 cm(2)V(-1)s(-1)), low threshold voltage (1.95 V), and excellent I-on/I-off ratio (similar to 10(4)) are achieved on SnO TFTs with a SiO2 gate dielectric after an annealing of 30 min. (C) 2016 The Japan Society of Applied Physics
Impact of gate dielectrics and oxygen annealing on tin-oxide thin-film transistors
(2016-04-01)
Zhong, Chia-Wen
;
Lin, Horng-Chih
;
Tsai, Jung-Ruey
;
Liu, Kou-Chen
;
Huang, Tiao-Yuan
In this work, we study the impact of gate dielectrics on the characteristics of bottom-gated tin-oxide thin-film transistors annealed in an oxygen ambience at 300 degrees C for various periods. SiO2, HfO2, and Al2O3 are employed as the gate dielectric in the test devices. The results show that the devices will start exhibiting p-type conduction behavior as the annealing reaches a specific time period which is closely related to the underlying gate dielectric, and the device characteristics can be improved as the annealing proceeds further. Nonetheless, a prolonged annealing may cause degradation of the devices. High hole mobility (3.33 cm(2)V(-1)s(-1)), low threshold voltage (1.95 V), and excellent I-on/I-off ratio (similar to 10(4)) are achieved on SnO TFTs with a SiO2 gate dielectric after an annealing of 30 min. (C) 2016 The Japan Society of Applied Physics
Impact of thermal oxygen annealing on the properties of tin oxide films and characteristics of p-type thin-film transistors
(2016-01-01)
Zhong, Chia-Wen
;
Lin, Horng-Chih
;
Liu, Kou-Chen
;
Huang, Tiao-Yuan
;
電子工程學系及電子研究所
In this work, we study the properties of tin oxide films, which were annealed in oxygen ambient for various periods. The as-deposited tin oxides are tin-dominant and, from the Hall measurements, they are of the n-type with high electron concentrations (>10(19) cm(-3)) and would change to the p-type when the oxygen annealing is sufficiently long. We have also found that changes in the structure and crystallinity of the channel layer can be clearly observed by X-ray diffraction analysis and optical microscopy. On the basis of the observations, a physical scheme is proposed to describe the evolution of the electrical performance of oxygen-annealed devices. A hole mobility of 3.24 cm(2) V-1 s(-1), a subthreshold swing of 0.43V/dec, a threshold voltage of 1.4V, and an on/off current ratio larger than 10(3) are obtained as the channel is transformed into SnO. (C) 2016 The Japan Society of Applied Physics
Impact of thermal oxygen annealing on the properties of tin oxide films and characteristics of p-type thin-film transistors
(2016-01)
Zhong, Chia-Wen
;
Lin, Horng-Chih
;
Liu, Kou-Chen
;
Huang, Tiao-Yuan
;
電子工程學系及電子研究所
In this work, we study the properties of tin oxide films, which were annealed in oxygen ambient for various periods. The as-deposited tin oxides are tin-dominant and, from the Hall measurements, they are of the n-type with high electron concentrations (>10(19) cm(-3)) and would change to the p-type when the oxygen annealing is sufficiently long. We have also found that changes in the structure and crystallinity of the channel layer can be clearly observed by X-ray diffraction analysis and optical microscopy. On the basis of the observations, a physical scheme is proposed to describe the evolution of the electrical performance of oxygen-annealed devices. A hole mobility of 3.24 cm(2) V-1 s(-1), a subthreshold swing of 0.43V/dec, a threshold voltage of 1.4V, and an on/off current ratio larger than 10(3) are obtained as the channel is transformed into SnO. (C) 2016 The Japan Society of Applied Physics
Improving Electrical Performances of p-Type SnO Thin-Film Transistors Using Double-Gated Structure
(2015-10-01)
Zhong, Chia-Wen
;
Lin, Horng-Chih
;
Liu, Kou-Chen
;
Huang, Tiao-Yuan
;
電子工程學系及電子研究所
p-type SnO thin-film transistors (TFTs) using a nominally symmetrical double-gated (DG) structure were studied in this letter. The top and bottom gates can be biased independently (single-gated mode) or jointly to switch the device (DG mode). For the latter operation, it is shown that ON current, subthreshold swing, and OFF-state current of the SnO TFT are all improved as compared with the operations when only one of the two gates is biased. As the device is operated under the DG mode, field-effect mobility of 6.54 cm(2)/V-s, high ON/OFF current ratio of >10(5), and subthreshold swing of 143 mV/decade are obtained. Moreover, the capability of the device in tuning its transfer characteristics under the single-gated operation with the bias applied to the opposite gate is also confirmed.
Resistive switching characteristics of multilayered (HfO2/Al2O3)(n) n=19 thin film
(2012-02-01)
Tzeng, Wen-Hsien
;
Zhong, Chia-Wen
;
Liu, Kou-Chen
;
Chang, Kow-Ming
;
Lin, Horng-Chih
A transparent resistive random access memory used as Indium Tin Oxide (ITO) electrode, ITO/HfO2/Al2O3/center dot center dot center dot/HfO2/Al2O3/ITO capacitor structure is fabricated on glass substrate by atomic layer deposition. The unipolar resistive switching characteristics can be performed by applying the positive- or negative-bias through top electrode, however, the differences of switching and stability in the two different operations can be observed. The diversities of electrical property are attributed to different oxide/ITO interface materials, which influence the current flow of the injected electrons. Crown Copyright (c) 2011 Published by Elsevier B.V. All rights reserved.