Browsing by Author "Lin, Chih-Yang"

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A characteristic improved technique and analysis with plasma treatment to the electrode on oxide-based resistive random access memory
(2020-03-15)
Lin, Chih-Yang
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Chang, Ting-Chang
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Pan, Chih-Hung
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Chen, Min-Chen
;
Xu, You-Lin
A technique was proposed to concentrate the distribution of set voltages. After a plasma treatment, the stability of the high-resistive state (HRS) increased, and the distribution of set voltages was more concentrated at 0.8 V, with a sufficient HRS/LRS resistive ratio (similar to 100x). In addition, the surface of the TiN electrode became rougher, causing oxygen to enter the TiN electrode and form a TiON layer, which acts as an oxygen reservoir. The reservoir is confirmed and the conduction model is supported by both electrical and material analyses. We propose that the observed improvement is due to the difference in the TiN electrode surface. (C) 2019 Published by Elsevier B.V.
A study of grid artifacts formation and elimination in computed radiographic images
(2006-12-01)
Lin, Chih-Yang
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Lee, Wen-Jeng
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Chen, Shyh-Jye
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Tsai, Ching-Hwa
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Lee, Jei-Han
Computed radiography (CR) has many advantages such as filmless operations, efficiency, and convenience. Furthermore, it is easier to integrate with the picture archiving and communication systems. Another important advantage is that CR images generally have a wider dynamic range than conventional screen film. Unfortunately, grid artifacts and moire pattern artifacts may be present in CR images. These artifacts become a more serious problem when viewing CR images on a computer monitor when a clinic grade monitor is not available. Images produced using a grid with higher frequency or a Potter-Bucky grid (i.e., a moving grid, Bucky for short) can reduce occurrence but cannot guarantee elimination of these artifacts [CR & PACS (2000); Detrick F (2001), pp 7-8]. In this paper, the formation of the artifacts is studied. We show that the grid artifacts occur in a narrow band of frequency in the frequency domain. The frequency can be determined, accurately located, and thus removed from the frequency domain. When comparing the results obtained from the proposed method against the results obtained using previous computer methods, we show that our method can achieve better image quality.
A Universal Model for Interface-type Threshold Switching Phenomena by Comprehensive Study of Vanadium Oxide-Based Selector
(2017-01-01)
Lin, Chih-Yang
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Chen, Ying-Chen
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Gu, Meiqi
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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.
Abnormal High Resistive State Current Mechanism Transformation in Ti/HfO2/TiN Resistive Random Access Memory
(2020-02-01)
Zhou, Kuan-Ju
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Chang, Ting-Chang
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Lin, Chih-Yang
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Chen, Chun-Kuei
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Tseng, Yi-Ting
In this letter, the electrical characteristics of Ti/HfO2/TiN resistive random access memory (RRAM) were thoroughly investigated. An abnormal current degradation was seen in the DC sweeping cycle. Both the on-state and off-state current clearly exhibited degradation with time. Next, current fitting analysis was used to investigate the carrier transport mechanisms. The results indicate that the on-state carrier transport mechanism changed from space-charge-limited current into hopping conduction after cycle sweeping. However, the off-state current changes from Schottky thermal emission to hopping conduction. Based on comparisons of different Schottky distances and Schottky barriers, physical models were proposed to explain the abnormal current degradation behavior. Finally, COMSOL electric field simulations were used to show the electric field distribution around the conducting filament (CF), and the conducting model was subsequently verified.
Amphiregulin promotes cisplatin chemoresistance by upregulating ABCB1 expression in human chondrosarcoma
(2020-05-31)
Huang, Yu-Wen
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Lin, Chih-Yang
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Tsai, Hsiao-Chi
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Fong, Yi-Chin
;
Han, Chien-Kuo
Chondrosarcomas are well known for their resistance to chemotherapeutic agents, including cisplatin, which is commonly used in chondrosarcomas. Amphiregulin (AR), a ligand of epidermal growth factor receptor (EGFR), plays an important role in drug resistance. We therefore sought to determine the role of AR in cisplatin chemoresistance. We found that AR inhibits cisplatin-induced cell apoptosis and promotes ATP-binding cassette subfamily B member 1 (ABCB1) expression, while knockdown of ABCB1 by small interfering RNA (siRNA) reverses these effects. High phosphoinositide 3-kinase (PI3K), Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappa B) phosphorylation levels were observed in cisplatin-resistant cells. Pretreating chondrosarcoma cells with PI3K, Akt and NF-kappa B inhibitors or transfecting the cells with p85, Akt and p65 siRNAs potentiated cisplatin-induced cytotoxicity. In a mouse xenograft model, knockdown of AR expression in chondrosarcoma cells increased the cytotoxic effects of cisplatin and also decreased tumor volume and weight. These results indicate that AR upregulates ABCB1 expression through the PI3K/Akt/NF-kappa B signaling pathway and thus contributes to cisplatin resistance in chondrosarcoma.
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
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Chen, Po-Hsun
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Chang, Ting-Chang
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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.
Automatic method to compare the lanes in gel electrophoresis images
(2007-03-01)
Lin, Chih-Yang
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Ching, Yu-Tai
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Yang, Yun-Liang
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生物科技學系
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資訊工程學系
Gel electrophoresis (GE) is an important tool in genomic analysis. GE results are presented using images. Each image contains several vertical lanes. Each lane consists of several horizontal bands. Two lanes are identical if the relative positions of the bands are the same. We present a computer method designed to compare the lanes and identify identical lanes. This method, developed using many image-processing techniques, is applied to segment the lanes and bands in GE images. The lanes are then converted into "position vectors" that describe the positions of the bands. Comparing lanes becomes equivalent to comparing the position vectors. This method can accurately identify identical lanes, helping biologists to identify the identical lanes from many lanes with much less effort.
Bistable resistive switching in Al2O3 memory thin films
(2007)
Lin, Chih-Yang
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Wu, Chen-Yu
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Wu, Chung-Yi
;
Hu, Chenming
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Tsenga, Tseung-Yuen
In this study, we investigate the resistive switching behavior of radio frequency (rf)-sputtered Al2O3 thin films. It is observed that both high-conducting state (ON state) and low-conducting state (OFF state) are stable and reproducible during successive resistive switchings by dc voltage sweeping. The ratio of resistance of the ON and OFF state is over 10(3). Such a reproducible resistive switching can be performed at 150 degrees C, and the resistance of the ON state can be altered by various current compliances. The conduction mechanisms of the ON and OFF states are demonstrated as ohmic conduction and Frenkel-Poole emission, respectively. Both states, performed by dc voltage sweeping and applying short pulse, are stable over 10(4) s at a read voltage of 0.3 V and the electrical-pulse-induced resistance change (EPIR) phenomenon is demonstrated, which are all important properties for further resistive random access memory application. (c) 2007 The Electrochemical Society.
CCN6-mediated MMP-9 activation enhances metastatic potential of human chondrosarcoma
(2018-09-20)
Tzeng, Huey-En
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Tang, Chih-Hsin
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Wu, Sz-Hua
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Chen, Hsien-Te
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Fong, Yi-Chin
Chondrosarcomas are primary malignant bone tumors that have a poor prognosis. WNT1-inducible signaling pathway protein-3 (WISP-3, also termed CCN6) belongs to the CCN family of proteins and is implicated in the regulation of various cellular functions, such as cell proliferation, differentiation, and migration. It is unknown as to whether CCN6 affects human chondrosarcoma metastasis. We show how CCN6 promotes chondrosarcoma cell migration and invasion via matrix metallopeptidase-9 (MMP)-9 expression. These effects were abolished by pretreatment of chondrosarcoma cells with PI3K, Akt, mTOR, and NE-KB inhibitors or short interfering (si)RNAs. Our investigations indicate that CCN6 facilitates metastasis through the PI3K/Akt/mTOR/NE-KB signaling pathway. CCN6 and MMP-9 expression was markedly increased in the highly migratory JJ012(S10) cell line compared with the primordial cell line (JJ012) in both in vitro and in vivo experiments. CCN6 knockdown suppressed MMP-9 production in JJ012(S10) cells and attenuated cell migration and invasion ability. Importantly, CCN6 knockdown profoundly inhibited chondrosarcoma cell metastasis to lung. Our findings reveal an important mechanism underlying CCN6-induced metastasis and they highlight the clinical significance between CCN6 and MMP-9 in regard to human chondrosarcoma. CCN6 appears to be a promising therapeutic target in chondrosarcoma metastasis.
Computer Aided Alignment and Quantitative 4D Structural Plasticity Analysis of Neurons
(2013-04-01)
Lee, Ping-Chang
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He, Hai-yan
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Lin, Chih-Yang
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Ching, Yu-Tai
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Cline, Hollis T.
The rapid development of microscopic imaging techniques has greatly facilitated time-lapse imaging of neuronal morphology. However, analysis of structural dynamics in the vast amount of 4-Dimensional data generated by in vivo or ex vivo time-lapse imaging still relies heavily on manual comparison, which is not only laborious, but also introduces errors and discrepancies between individual researchers and greatly limits the research pace. Here we present a supervised 4D Structural Plasticity Analysis (4D SPA) computer method to align and match 3-Dimensional neuronal structures across different time points on a semi-automated basis. We demonstrate 2 applications of the method to analyze time-lapse data showing gross morphological changes in dendritic arbor morphology and to identify the distribution and types of branch dynamics seen in a series of time-lapse images. Analysis of the dynamic changes of neuronal structure can be done much faster and with greatly improved consistency and reliability with the 4D SPA supervised computer program. Users can format the neuronal reconstruction data to be used for this analysis. We provide file converters for Neurolucida and Imaris users. The program and user manual are publically accessible and operate through a graphical user interface on Windows and Mac OSX.
Constructing Neuronal Structure from 3D Confocal Microscopic Images
(2009)
Lee, Ping-Chang
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Chang, Hsiu-Ming
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Lin, Chih-Yang
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Chiang, Ann-Shyn
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Ching, Yu-Tai
A semiautomatic method, based on the gradient flow (GVF) snake, to construct the neuronal structure from 3D confocal microscopic images is presented. A single neuron can be labeled by using green fluorescent protein (GFP) such that the 3D neuronal structure can be visualized in a stack of confocal microscopic images. To construct the neuronal structure, we traced a target fiber by providing a rough initial path to approximate that fiber. The path is then deformed under the gradient vector field to converge to the centerline of the fiber by using the GVF snake method. Using our developed software, a neuronal sturctural can be efficiently reconstructed and the tracing results can be reduced to the tree structure of the neuron. Given the tree structure of the neuron, quantitative information can be derived and further analysis can be carried out.
Current status of resistive nonvolatile memories
(2008-12-01)
Lin, Chih-Yang
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Liu, Chih-Yi
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Lin, Chun-Chieh
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Tseng, T. Y.
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電子工程學系及電子研究所
Several emerging nonvolatile memories (NVMs) such as ferroelectric memory, magnetoresistive rams and ovonic universal memory are being developed for possible applications. Resistive random access memory (RRAM) is another interesting competitor in the class of NVMs. The RRAM is based on a large change in electrical resistance when the memory film is exposed to voltage or current pulses, and can keep high or low resistance states without any power. The ideal RRAM Should have the superior properties of reversible switching, long retention tune, multilevel switching, simple structure, small size, and low operating voltage. Perovskite oxides, transition metal oxides, and molecular materials were found to have resistive memory properties. This presentation reviews the ongoing research and development activities on future resistance NVMs technologies incorporating these new memory materials. The possible basic mechanisms for their bistable resistance switching are described. The effect of processing, composition, and structure on the properties of resistive memory materials and consequently the devices are discussed.
Effect of thermal treatment on resistive switching characteristics in Pt/Ti/Al(2)O(3)/Pt devices
(2008-12-25)
Lin, Chih-Yang
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Lee, Dai-Ying
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Wang, Sheng-Yi
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Lin, Chun-Chieh
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Tseng, Tseung-Yuen
Resistive switching characteristics of Pt/Ti/Al(2)O(3)/Pt memory devices annealed at various temperatures including 400 degrees C, 500 degrees C and 600 degrees C for 1 h under ambient condition were investigated in the study. The Al(2)O(3) thin films annealed at up to 600 degrees C for 1 h remain amorphous phase based on the X-ray diffraction (XRD) analyses. As increasing annealing temperature, the forming voltage (activating the pristine device) of the memory device decreases in contrast to the rising trend of the turn-on voltage (switching from high to low resistance state). However, the turn-off voltage (switching from low to high resistance state) is almost uninfluenced by thermal annealing. These phenomena might be attributed to the interdiffusion between Ti and Al(2)O(3), based on the analyzed results of secondary ion mass spectroscopy (SIMS) and high resolution transmission electron microscope (HR-TEM). Moreover, the thermal annealing process eventually creates high conducting paths with a high density of oxygen vacancies between the two electrodes. (c) 2008 Elsevier B.V. All rights reserved.
Effect of thermal treatment on resistive switching characteristics in Pt/Ti/Al2O3/Pt devices
(2008-12-25)
Lin, Chih-Yang
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Lee, Dai-Ying
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Wang, Sheng-Yi
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Lin, Chun-Chieh
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Tseng, Tseung-Yuen
Resistive switching characteristics of Pt/Ti/Al2O3/Pt memory devices annealed at various temperatures including 400 degrees C, 500 degrees C and 600 degrees C for 1 h under ambient condition were investigated in the study. The Al2O3 thin films annealed at up to 600 degrees C for 1 h remain amorphous phase based on the X-ray diffraction (XRD) analyses. As increasing annealing temperature, the forming voltage (activating the pristine device) of the memory device decreases in contrast to the rising trend of the turn-on voltage (switching from high to low resistance state). However, the turn-off voltage (switching from low to high resistance state) is almost uninfluenced by thermal annealing. These phenomena might be attributed to the interdiffusion between Ti and Al2O3, based on the analyzed results of secondary ion mass spectroscopy (SIMS) and high resolution transmission electron microscope (HR-TEM). Moreover, the thermal annealing process eventually creates high conducting paths with a high density of oxygen vacancies between the two electrodes. (c) 2008 Elsevier B.V. All rights reserved.
Effect of top electrode material on resistive switching properties of ZrO2 film memory devices
(2007-05-01)
Lin, Chih-Yang
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Wu, Chen-Yu
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Wu, Chung-Yi
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Lee, Tzyh-Cheang
;
Yang, Fu-Liang
The influence of top electrode material on the resistive switching properties of ZrO2 -based memory film using Pt as a bottom electrode was investigated in this letter. In comparison with Pt/ZrO2/Pt and Al/ZrO2/Pt devices, the Ti/ZrO2/Pt device exhibits different resistive switching current-voltage (I-V) curve, which can be traced and reproduced by a dc voltage more than 1000 times only showing a little decrease of resistance ratio between high and low resistance states. Furthermore, the broad dispersions of resistive switching characteristics in the Pt/ZrO2/Pt and Al/ZrO2/Pt devices are generally observed during successive resistive switching, but those dispersions are suppressed by the device using Ti as a top electrode. The reliability results, such as cycling endurance and continuous readout test, are also presented. The write-read-erase-read operations can be over 104 cycles without degradation. No data loss is found upon successive readout after performing various endurance cycles.
Effects of erbium doping of indium tin oxide electrode in resistive random access memory
(2016-03)
Chen, Po-Hsun
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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
Identical insulators and bottom electrodes were fabricated and capped by an indium tin oxide (ITO) film, either undoped or doped with erbium (Er), as a top electrode. This distinctive top electrode dramatically altered the resistive random access memory (RRAM) characteristics, for example, lowering the operation current and enlarging the memory window. In addition, the RESET voltage increased, whereas the SET voltage remained almost the same. A conduction model of Er-doped ITO is proposed through current-voltage (I-V) measurement and current fitting to explain the resistance switching mechanism of Er-doped ITO RRAM and is confirmed by material analysis and reliability tests. (C) 2016 The Japan Society of Applied Physics
Effects of Ti top electrode thickness on the resistive switching behaviors of rf-sputtered ZrO(2) memory films
(2009-09-14)
Wang, Sheng-Yu
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Lee, Dai-Ying
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Tseng, Tseung-Yuen
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Lin, Chih-Yang
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電子工程學系及電子研究所
In this study, we propose a simple method to produce the various interface thicknesses within Ti/ZrO(2) by changing the thickness of the Ti top electrode. As the Ti thickness increases, the induced interface thickness also increases to degrade the dielectric strength of the ZrO(2), further lowering the forming voltage. However, when the interface layer is thick enough, it will trap sufficient charges to build up an opposite electric field to increase the forming voltage. The induced interface thickness is found to obviously affect the bias polarity of the resistive switching behavior and the device reliability. A fluctuant ON process is also demonstrated to be attributed to the competition between the formation and rupture of the conducting filaments. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3231872]
Effects of Ti top electrode thickness on the resistive switching behaviors of rf-sputtered ZrO2 memory films
(2009-09-14)
Wang, Sheng-Yu
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Lee, Dai-Ying
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Tseng, Tseung-Yuen
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Lin, Chih-Yang
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電子工程學系及電子研究所
In this study, we propose a simple method to produce the various interface thicknesses within Ti/ZrO2 by changing the thickness of the Ti top electrode. As the Ti thickness increases, the induced interface thickness also increases to degrade the dielectric strength of the ZrO2, further lowering the forming voltage. However, when the interface layer is thick enough, it will trap sufficient charges to build up an opposite electric field to increase the forming voltage. The induced interface thickness is found to obviously affect the bias polarity of the resistive switching behavior and the device reliability. A fluctuant ON process is also demonstrated to be attributed to the competition between the formation and rupture of the conducting filaments. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3231872]
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.
Efficient Triple Output Network for Vertebral Segmentation and Identification
(2019-01-01)
Chuang, Cheng-Hung
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Lin, Chih-Yang
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Tsai, Yuan-Yu
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Lian, Zhen-You
;
Xie, Hong-Xia
Precise vertebral segmentation provides the basis for spinal image analyses and interventions, such as vertebral compression fracture detection and other abnormalities. Deep learning is a popular and useful paradigm for medical image process. In this paper, we proposed an iterative vertebrae instance segmentation model, which has good generalization ability for segmenting all types of vertebrae, including cervical, thoracic, and lumbar vertebrae. In experimental results, our model not only used 17% less memory but also achieves better performance on vertebrae segmentation compared to existing methods. The existing method provides only two output for segmentation and classification respectively. However, with more memory available, our model is capable of providing third output for accurate anatomical prediction under the same amount of memory.