Browsing by Issue Date, starting with "2007-12-03"

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Tungsten nanocrystal memory devices improved by supercritical fluid treatment
(2007-12-03)
Chen, C. H.
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Chang, T. C.
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Liao, I. H.
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Xi, P. B.
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Tsai, C. T.
A supercritical CO(2) (SCCO(2)) fluid technique is proposed to improve electrical characteristics for W nanocrystal nonvolatile memory devices, since the thickness and quality of tunnel oxide are critical issues for the fabrication of nonvolatile memory devices. After SCCO(2) treatments, C-V curves are restored to normal, as well as the leakage current of W nanocrystal memory devices are reduced significantly. It reveals that W nanocrystal memory devices could be formed with shorter oxidation time, moreover, dangling bonds and trapping states initially created within an incomplete oxidized film will be efficiently repaired after SCCO(2) treatment. (c) 2007 American Institute of Physics.
Memory effect of RF sputtered ZrO2 thin films
(2007-12-03)
Lin, Chih-Yang
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Wu, Chung-Yi
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Wu, Chen-Yu
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Lin, Chun-Chieh
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Tseng, Tseung-Yuen
Electrical properties of RF sputtered ZrO2 Memory thin films were investigated in this study. The device with structure AI/ZrO2/Pt shows a reproducible resistive switching behavior traced over 100 times at room temperature. Moreover, by using various top electrodes, such as Pt, Cu, Ni, Ag, Ti, and even W-probe, the resistive switching phenomenon can be observed in ZrO2-based memory with Pt bottom electrode, indicating that the ZrO2 bulk dominates the resistive switching. The bias polarity dependent resistive switching behavior is demonstrated in the Ti/ZrO2/Pt device, which might be due to interface reaction between Ti and ZrO2 film. The resistance value of high conductive state in the Ti/ZrO2/Pt device decreases with increasing current compliance implying the possibility for multi-bit storage. Besides, the Ti/ZrO2/Pt device can be operated over 2000 resistive switching cycles at 85 degrees C by sweeping DC voltage, and the two memory states demonstrate good stability under read voltage stress at room temperature and 95 degrees C. The write-read-erase-read operations can be over 10(3) cycles at 85 degrees C. No data loss is found upon successive readout before and after performing 10(3) endurance cycles at 85 degrees C. According to above experimental results, the ZrO2 thin film has high potential for nonvolatile memory application. (C) 2007 Elsevier B.V. All rights reserved.
Highly efficient p-i-n white organic light emitting devices with tandem structure
(2007-12-03)
Ho, Meng-Huan
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Chen, Teng-Ming
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Yeh, Pu-Cheng
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Hwang, Shiao-Wen
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Chen, Chin H.
Highly efficient tandem p-i-n white organic light emitting devices have been fabricated. Utilizing an optical transparent bilayer with doped organic p-n junction that consists of 4,7-diphenyl-1,10-phenanthroline: 2% cesium carbonate (Cs(2)CO(3))/N,N(')-bis(1-naphthyl)-N,N(')-diphenyl-1,1(')-biphenyl-4,4(')-diamine: 50% v/v tungsten oxide (WO(3)) as the connecting layer, the tandem p-i-n white device achieved an electroluminescence efficiency of 23.9 cd/A and a power efficiency of 7.8 lm/W at 20 mA/cm(2) with a Commission Internationale de l'Eclairage coordinates of (0.30, 0.43). The electroluminescent color of this tandem p-i-n white organic light-emitting diode device will not change significantly with respect to drive current variation and forward viewing angle. (c) 2007 American Institute of Physics.
A Cu-based alloyed ohmic contact system on n-type GaAs
(2007-12-03)
Chen, Ke-Shian
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Chang, Edward Yi
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Lin, Chia-Ching
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Lee, Cheng-Shih
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Huang, Wei-Ching
An alloyed Pd/Ge/Cu Ohmic contact to n-type GaAs is reported for the first time. The Pd/Ge/Cu Ohmic contact exhibited a very low specific contact resistance of 5.73x10(-7) Omega cm(2) at a low annealing temperature of 250 degrees C. This result is comparable to the reported Pd/Ge and Au/Ge/Ni Ohmic contact systems to n-type GaAs with doping concentrations about 1x10(18) cm(-3). The Ohmic contact formation mechanisms and microstructure evolution were investigated using secondary ion mass spectrometry, x-ray diffraction, transmission electron microscopy, and energy dispersive spectrometer. The Ohmic contact behavior was related to the formation of Cu(3)Ge and PdGa(x)As(y) compounds after annealing. (c) 2007 American Institute of Physics.
Structural and optical properties of Al-doped ZnO nanowires synthesized by hydrothermal method
(2007-12-03)
Bai, S. N.
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Tsai, H. H.
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Tseng, T. Y.
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The growth of one dimensional Al-doped ZnO nanowires on a silicon substrate with a ZnO seeding layer by using a low temperature hydrothermal method is demonstrated. The structural and optical characteristics of the solution-grown Al-doped ZnO nanowires were studied using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and cathodoluminescence (CL) measurements. The FE-SEM images show that the ZnO nanowires are hexagonal column shaped and stand perpendicularly on the silicon substrate. It is found in XRD patterns that the ZnO nanowires annealed at various temperatures are all wurtzite crystal structure and have (002) preferred orientation. As the annealing temperature changed, the intensity of (100) and (10 1) peaks reveals distinct change. The CL spectra show the as-grown ZnO nanowires display a weak and narrow UVemission centered at 376 nm. A strong and very broad green-yellow emission band with a center at 575 nm as well as a shoulder like orange-red emission band centering at 625 nm is also demonstrated. It is shown that the luminescence intensity centered at 376 nm increased, the shoulder like emission centered at 625 nm decreased but emission centered at 575 nm disappeared after thermal annealing treatment in oxygen atmosphere. (C) 2007 Elsevier B.V. All rights reserved.
Photo-induced hydrophilicity of TiO2-N-x(x) thin films on PET plates
(2007-12-03)
Chou, Hsiu-Yu
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Lee, En-Ko
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You, Jiang-Wen
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Yu, Sung-Shih
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電子工程學系及電子研究所
TiO2-xNx thin films were deposited on PET (polyethylene terephthalate) plates by sputtering a TiN target in a N-2/O-2 plasma and without heating. X-ray photoemission spectroscopy (XPS) was used to investigate the N 1s, Ti 2p core levels and the nitrogen composition in the TiO2-xNx films. The results indicate that Ti-O-N bonds are formed in the thin films. Two nitrogen states, substitution and interstitial nitrogen atoms, were attributed to peaks at 396 and 399 eV, respectively. It was observed that the nitrogen atoms occupy both the substitutive and interstitial sites in respective of the nitrogen content in the thin films. UV-VIS absorption spectroscopy of PET coated thin films shows a significant shift of the absorption edge to lower energy in the visible-light region. UV and visible-light irradiation are used to activate PET coated thin films for the development of hydrophilicity. The photo-induced surface wettability conversion reaction of the thin films has been investigated by means of water contact angle measurement. PET plates coated with TiO2-xNx thin films are found to exhibit lower water contact angle than non-coated plates when the surface is illuminated with UV and visible light. The effects of nitrogen doping on photo-generated hydrophilicity of the thin films are investigated in this work. (C) 2007 Elsevier B.V. All rights reserved.
Source-drain barrier height engineering for suppressing the a-Si : H TFTs photo leakage current
(2007-12-03)
Wang, M. C.
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Chang, T. C.
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Liu, P. T.
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Li, Y. Y.
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Huang, F. S.
For effectively reducing the off-state signal loss resulted from the a-Si:H TFTs photo leakage current, the a-Si:H TFTs with the use of ITO as source-drain metal have been fabricated for this study. Several TFT structures have been fabricated to examine this characteristic. A remarkable reduction in photo leakage current has been observed under the 3300 cd/m(2) CCFL backlight illumination. The source-drain barrier height engineering has been proposed for these results. According to the energy band diagram, the barrier height for hole is estimated about 3 eV. As a result, the photo-generation holes blocked in the source-drain barrier height could effectively reduce the photo leakage current in off-state. (C) 2007 Elsevier B.V. All rights reserved.
Stable resistive switching behaviors of sputter deposited V-doped SrZrO3 thin films
(2007-12-03)
Lin, Chun-Chieh
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Yu, Jung-Sheng
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Lin, Chih-Yang
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Lin, Chen-Hsi
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Tseng, Tseung-Yuen
The influences of doping concentration and element on the resistive switching properties of SZO-based memory devices are investigated in this study. The sputter-deposited LNO bottom electrode and SZO resistive layer exhibit (100)-preferred orientation, and the LNO film annealed at 600 degrees C performs smooth surface and high conductivity. The 0.3% V:SZO memory device depicts the good switching behaviors including high resistance ratio, high endurance, long retention time, and non-destructive readout property. The turn-on voltage is slightly dependent on the SZO thickness, while the turn-off voltage is almost irrelative to the thickness. Besides, the switching properties of MoO3-, MoO2-, and Cr2O3-doped SZO devices are also studied. The results demonstrate that the resistive switching is an intrinsic property of the SZO film, but proper doping concentration and element can improve and stabilize the resistive switching behaviors. (C) 2007 Elsevier B.V. All rights reserved.
Fabrication of superhydrophobic and superoleophilic polystyrene surfaces by a facile one-step method
(2007-12-03)
Tu, Cheng-Wei
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Tsai, Chia-Hua
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Wang, Chih-Feng
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Kuo, Shiao-Wei
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Chang, Feng-Chih
A facile one-step method has been developed to prepare both superhydrophobic and superoleophilic surfaces of polystyrene (PS) without any chemical modification. A rough film consisting of micro-bead and nano-fiber mixed structures is formed by spraying a PS solution onto a large area and any type of substrate. The mixed structures with such unique wettability properties can be used in oil/water separation and as oil sorbents.
Nickel silicide nanocrystals embedded in SiO2 and HfO2 for nonvolatile memory application
(2007-12-03)
Yang, F. M.
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Chang, T. C.
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Liu, Po-Tsun
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Yeh, Y. H.
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Yu, Y. C.
In this study, a nonvolatile memory device with NiSi2 nanocrystals embedded in the SiO2 and HfO2 layer has been fabricated. A significant memory effect is observed during the characterization of the electrical properties. When a low operating voltage, 4 V, is applied, a significant threshold voltage shift of 1.3 V, is observed. The processing of this structure is compatible with the current manufacturing technology of semiconductor industry. (C) 2007 Published by Elsevier B.V.
Thickness-dependent microstructures and electrical properties of CaCu3Ti4O12 films derived from sol-gel process
(2007-12-03)
Chang, Li-Chun
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Lee, Dai-Ying
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Ho, Chia-Cheng
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Chiou, Bi-Shiou
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電子工程學系及電子研究所
CaCu3Ti4O12 (CCTO) thin films with various thicknesses were prepared by a sol-gel multiple coating processes on Pt/Ti/SiO2/Si substrates. Microstructures and surface morphologies of CCTO thin films were analyzed by grazing incident X-ray diffractometer (GIXRD) and scanning electron microscope (SEM), respectively. The correlation between the thickness and electrical properties of CCTO films was investigated. The dielectric constants of CCTO films decreased with increasing film thickness (coating cycle). Both the dielectric constant of CCTO films and interlayer are calculated. Possible mechanisms are explored to explain the thickness dependence of the dielectric constant of CCTO films. (C) 2007 Elsevier B.V. All rights reserved.
Investigation of the low dielectric siloxane-based hydrogen silsesquioxane (HSQ) as passivation layer on TFT-LCD
(2007-12-03)
Chang, Ta-Shan
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Chang, Ting-Chang
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Liu, Po-Tsun
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Tsao, Shu-Wei
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Yeh, Feng-Sheng
Spin-on low-k passivation is achieved on inverted-staggered back-channel-etched hydrogenated amorphous silicon thin-film transistors (TFT). The low-k passivation material, siloxane-based hydrogen silsesquioxane (HSQ), has been investigated for different process temperatures. Performance is improved with decreased temperature. At 300 degrees C, the TFT performance of HSQ passivation is superior to those of other TFTs. The hydrogen bonds of HSQ assist hydrogen incorporation to eliminate the density of states between the back channel and the passivation layer. The characteristics of HSQ passivated TFT have been studied in this work. (C) 2007 Published by Elsevier B.V.
交大e-News第015期
(2007-12-05)
Secretariat
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國立交通大學秘書室
Method and apparatus for self-compensation on belief-propagation algorithm
(2007-12-06)
Liao, Yen-Chin
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Lin, Chien-Ching
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Chang, Hsie-Chia
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Liu, Chih-Wei
A self-compensation method includes: firstly using a min-sum algorithm to derive multiple output values in order to approach a operational result of the checking side of a belief-propagation; and then checking the present iteration number of decoding based on a checking rule; and finally, if in the previous step the present iteration number is identified with a to-be-corrected state, then performing a compensation procedure on the multiple output values, wherein the compensation term is dynamically selected in accordance with an input value of the checking nodes of the belief-propagation. The invention also provides an automatic compensation apparatus, which consists of devices such as a min-sum operating unit, and a dynamic quantization control unit, etc., which can be used, while executing the invented method described above, to decode the belief-propagation algorithm.
Plasma suppression of large scale structure formation in the universe
(2007-12-07)
Chen, Pisin
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Lai, Kwang-Chang
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物理研究所
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Institute of Physics
We point out that during the reionization epoch of the cosmic history, the plasma collective effect among the ordinary matter would suppress the large scale structure formation. The imperfect Debye shielding at finite temperature would induce an electrostatic pressure which, working together with the thermal pressure, would counter the gravitational collapse. As a result, the effective Jeans length, (lambda) over tilde (J) is increased by a factor (lambda) over tilde (J)/(lambda) over tilde (J) = root 8/5, relative to the conventional one. For scales smaller than the effective Jeans scale the plasma would oscillate at the ion-acoustic frequency. The modes that would be influenced by this effect lie roughly in the range 0.5h Mpc(-1)< k, which corresponds to the Lyman-alpha forest from the intergalactic medium. We predict that in the linear regime of density-contrast growth, the plasma suppression of the matter power spectrum would approach 1 - (Omega(dm)/Omega(m))(2) similar to 1 - (5/6)(2) similar to 30%.
Comment on "Evaluation of the Hantush's M(alpha, beta) function using binomial coefficients" by B. A. Mamedov and A. S. Ekenoglu
(2007-12-07)
Yang, Shaw-Yang
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Yeh, Hund-Der
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環境工程研究所
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Institute of Environmental Engineering
《中國即將崩潰》
(2007-12-09)
林暐家
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Department of Communication and Technology
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傳播與科技學系
本書探討中國不穩定的經濟、社會層面，將不堪一擊的現實面一一揭露
生命重要還是方便重要？
(2007-12-09)
鄧詠兒
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Department of Communication and Technology
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傳播與科技學系
是要反映新竹交通混亂的情況,呈現新竹駕駛人和路人的實際情況,以及該有的態度
跨性者的美麗與哀愁—高旭寬
(2007-12-09)
李怡萱
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Department of Communication and Technology
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傳播與科技學系
跨性者的美麗與哀愁—高旭寬
錦繡小鎮　南庄故事多
(2007-12-09)
張雅雯
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Department of Communication and Technology
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傳播與科技學系
從文化產業看南庄