Browsing by Issue Date, starting with "2013-01-15"

Now showing 1 - 20 of 32673

Influence of forming process on resistance switching characteristics of In2O3/SiO2 bi-layer
(2013-01-15)
Huang, Jheng-Jie
;
Chang, Ting-Chang
;
Yang, Po-Chun
;
Chen, Yu-Ting
;
Tseng, Hsueh-Chih
In this study, we fabricated and analyzed resistance switching characteristics for resistance random access memory (RRAM) in a Pt/In2O3/SiO2/TiN structure. By applying opposing electric fields to performa soft breakdown of the In2O3/SiO2 insulating bi-layer, different switching behaviors are exhibited. When positive forming voltage was applied to the TiN electrode to soft breakdown the device, the resistance switching behavior was dominated by the bipolar mode. However, the negative voltage forming process exhibited both unipolar switching characteristics in addition to a bipolar switch mode. In order to analyze the composition of the conduction path and resistance switching mechanism, resistance value trends versus temperature was extracted and showed that the conduction paths of bipolar and unipolar modes are dominated by oxygen vacancies and metallic filament, respectively. Hence, metallic filament was considered to be formed by the migration of indium ions because the unipolar characteristic was only present during negative bias forming condition. (c) 2012 Elsevier B.V. All rights reserved.
Effect of thermal treatment on physical, electrical properties and reliability of porogen-containing and porogen-free ultralow-k dielectrics
(2013-01-15)
Chang, Yu-Min
;
Chang, Wei-Yuan
;
Huang, Jun-Fu
;
Leu, Jihperng
;
Cheng, Yi-Lung
The effects of thermal annealing on the physical, electrical properties and reliability of porogen-containing and porogen-free ultralow-k dielectrics prepared by plasma-enhanced chemical vapor deposition (PECVD) are investigated. The porogen-free low-k dielectrics are obtained by using UV curing process to removal organic sacrificial phase and to generate open porosity. The results are compared with PECVD porogen-containing low-k films fabricated without UV curing process and PECVD low-k dielectrics deposited without organic sacrificial phase. The experimental results show that all low-k films remained stable after they were experimentally heating to temperatures up to 700 degrees C. The non-porous low-k films also showed the highest reliability. Although the porous-free low-k film requires an additional UV curing process, the heat stress confirmed that its thermal stability was better than that of the porogen-containing low-k film. At an annealing temperature above 500 degrees C, the heating process is comparable to UV curing, but does not provide Si-O-Si cross-linking within the film. At an annealing of 600 degrees C, the porogen-free low-k films have a relatively higher breakdown electric-field and longer failure time in comparison to the porogen-containing low-k films. However, pores generated in porogen-containing low-k films at high temperature cause reliability to degrade with annealing temperature. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.
Morphology evolution of a-plane ZnO films on r-plane sapphire with growth by pulsed laser deposition
(2013-01-15)
Peng, Chun-Yen
;
Tian, Jr-Sheng
;
Wang, Wei-Lin
;
Ho, Yen-Teng
;
Chang, Li
In this study, the morphology evolution of epitaxial a-plane ZnO on r-plane sapphire at low and high temperatures with growth by pulsed laser deposition (PLD) are presented. Examination of the surfaces of ZnO films during growth was done with in situ reflection high energy electron diffraction, and atomic force microscopy was used to examine the surface morphology of the corresponding films after growth. For initial growth, it was observed that (1 x 2) reconstruction on ZnO grown at 750 degrees C (HT-ZnO) occurred with step-flow growth, while ZnO grown at 450 degrees C (LT-ZnO) exhibited island growth mode. For thick films both HT- and LT-ZnO surfaces eventually develop into stripe morphology. Significant change of surface morphology during cooling had also been observed. (C) 2012 Elsevier B.V. All rights reserved.
Enhanced cooling for LED lighting using ionic wind
(2013-01-15)
Chen, Ing Youn
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Guo, Mei-Zuo
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Yang, Kai-Shing
;
Wang, Chi-Chuan
;
機械工程學系
This study employs ionic wind to augment heat transfer of a LED mounted on a substrate. The size of the LED chip is 0.9 mm x 0.9 mm with a nominal power of 1 W. A needle type electrode is used to generate ionic wind with the applied voltage ranging from 4 to 11 kV. The effects of aligned angle, electrode polarity, separation distance, and ground configuration on the thermal resistance of the LED substrate are examined in this study. For the same applied voltage, it appears that the thermal resistance for the negative polarity is lower than that for the positive one and the negative electrode also has a wilder operation range. The thermal resistance can be reduced as much as 50% in the test range. The thermal resistance is slightly reduced when the aligned angle is increased from 0 degrees to 20 degrees, but a further increase of aligned angle casts no further reduction on the thermal resistance. It is found that the influence of vertical separation distance between the needle and ground electrode is moderately higher than that of horizontal separation distance. Test results also indicate that the mesh ground electrode shows moderately lower thermal resistance than those of point or line electrode. (C) 2012 Elsevier Ltd. All rights reserved.
Structure and property of epitaxial titanium oxynitride grown on MgO(001) substrate by pulsed laser deposition
(2013-01-15)
Do, Hien
;
Wu, Yue-Han
;
Van-Truong Dai
;
Peng, Chun-Yen
;
Yen, Tzu-Chun
High-quality epitaxial TiNxOy, films with different oxygen content were deposited on MgO(001) substrates by pulsed laser deposition method. The chemical composition of the deposited films was determined by X-ray photoelectron spectroscopy. X-ray diffraction results showed that the TiNxOy films are heteroepitaxially grown on MgO with good crystallinity and their lattice parameters decrease with increased oxygen concentration. Transmission electron microscopy analyses showed that TiNxOy films contain a low density of dislocations. Atomic force microscopy revealed very smooth surfaces of TiNxOy films with roughness of 026-0.29 nm. The resistivity of TiNxOy, films determined by Hall measurement was about 28-33 mu Omega cm. Nanoindentation measurements showed the film hardness and Young's modulus of about 23-26 GPa and 400-430 GPa, respectively. (C) 2012 Elsevier B.V. All rights reserved.
The resistive switching characteristics in TaON films for nonvolatile memory applications
(2013-01-15)
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
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.
How tantalum proceeds phase change on tantalum nitride underlayer with sequential Ar plasma treatment
(2013-01-15)
Tsao, Jung-Chih
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Liu, Chuan-Pu
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Fang, Hsin-Chiao
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Wang, Ying-Lang
;
光電學院
Tantalum can change its phase from high resistive beta-Ta to low resistive alpha-Ta phase on a TaN substrate with sequential Ar plasma treatment on the TaN layer surface prior to Ta deposition. The underlined mechanism of phase evolution is proposed based on systematic microstructure examination by high-resolution transmission electron microscopy. The images show that, with argon treatment, the upper part of the TaN film is transformed from amorphous-TaN to a composite phase of bcc-Ta(N) and amorphous-TaN mixture, which is also confirmed by X-ray diffraction patterns. The composite film composed of less nitrogen provides an ideal cubic matrix to confine the stable alpha-Ta phase to be grown. The alpha-Ta/bcc-Ta(N) film obtained by proper argon treatment results in film resistivity 10 times lower than the traditional Ta/TaN film. (C) 2012 Elsevier B.V. All rights reserved.
Impact of strain on gate-induced floating body effect for partially depleted silicon-on-insulator p-type metal-oxide-semiconductor-field-effect-transistors
(2013-01-15)
Lo, Wen-Hung
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Chang, Ting-Chang
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Dai, Chih-Hao
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Chung, Wan-Lin
;
Chen, Ching-En
This work investigates impact of mechanical strain on gate-induced-floating-body-effect (GIFBE) for partially depleted silicon-on-insulator p-type metal-oxide-semiconductor field effect transistors (PD SOI p-MOSFETs). First part, the original mechanism of GIFBE on PD SOI p-MOSFETs is studied. The experimental results indicate that GIFBE causes a reduction in oxide electric field (E-ox), resulting in an underestimate of negative-bias temperature instability (NBTI) degradation. This can be attributed to the electrons tunneling from the process-induced partial n(+) poly gate and anode electron injection (AEI) model, rather than the electron valence band tunneling (EVB) widely accepted as the mechanism for n-MOSFETs. And then, the second part shows that the strained FB device has less NBTI degradation than the unstrained devices. This behavior can be attributed to the fact that more electron accumulation was induced by strain-induced band gap narrowing, reducing NBTI significantly. (c) 2012 Elsevier B.V. All rights reserved.
Ligand and metal complex
(2013-01-15)
Wang Yun-Ming
;
Chen Ting-Jung
A ligand of Formula (I) is provided: wherein A4 represents a hydrogen atom, a nitro group, an amino group, a thiocyanato group, or —Z—Y, in which Z is a divalent linking group and Y is a group derived from a biocompatible molecule, with the proviso that when X is methylene, A4 cannot be a hydrogen atom or a nitro group. A metal complex having the ligand is also provided and is useful as a blood pool contrast agent or a targeting contrast agent.
一種電子顯微鏡樣品盒
(2013-01-16)
陳智
;
杜經寧
本發明係有關於一種電子顯微鏡樣品盒，包括：一第一基板、一第二基板、一或以上之光電元件、及一金屬黏著層。該第一基板具有一第一表面、一第二表面、一第一凹槽、及一或以上之第一導孔，該第一導孔係貫穿第一基板。該第二基板具有一第三表面、一第四表面、及一第二凹槽。該光電元件係設置於第一基板及第二基板間。另外，該金屬黏著層，係設置於該第一基板與該第二基板間以形成一空間，使樣品容置於其中。此外，本發明更包括一或以上之栓塞，係可密封第一導孔，使本發明之樣品盒密封並以電子顯微鏡即時觀測。
具磁控制之奈米孔洞型藥物載體
(2013-01-16)
陳三元
;
陳柏溶
;
劉典謨
;
胡尚秀
本發明提供一種具磁控制之奈米孔洞型藥物載體，其利用一無機或有機之基材來裝載藥物，作為藥物載體，並使用具有磁敏感性的磁性奈米粒子包覆於基材表面，以將藥物封圍起來。本發明之具磁控制之奈米孔洞型藥物載體可利用一外部磁場訊號來控制磁性奈米粒子的移除率，以控制藥物釋放行為及釋放量。
一種電子顯微鏡樣品盒
(2013-01-16)
陳智
;
杜經寧
本發明係有關於一種電子顯微鏡樣品盒，包括：一第一基板、一第二基板、及一金屬黏著層。該第一基板具有一第一表面、一第二表面、一第一凹槽、及一或以上之第一導孔，該第一導孔係貫穿第一基板。該第二基板具有一第三表面、一第四表面、及一第二凹槽。另外，該金屬黏著層，係設置於該第一基板與該第二基板間以形成一空間，使樣品容置於其中，此外，本發明更包括一或以上之栓塞，係可密封第一導孔，使本發明之樣品盒密封並以電子顯微鏡即時觀測。
載藥型隱形眼鏡及其製備方法
(2013-01-16)
劉典謨
;
劉佩鈴
本發明係揭露一種載藥型隱形眼鏡及其製備方法，此載藥型隱形眼鏡具有一隱形眼鏡本體，隱形眼鏡本體至少包含有一雙性混成奈米載體，其上係載有藥物分子。本發明更藉由藥物分子之光或熱敏感性差異，以分別製作出兩種不同類型的包覆型及浸藥型之載藥型隱形眼鏡。本發明係利用具有良好藥物包覆能力和生物相容性極高之雙性混成奈米載體包覆藥物分子，達到藥物分子長期緩慢釋放至眼睛組織裡，使藥物之損失、對人體產生副作用機率降至最低，以達到醫療、保健目的者。
可消除雜音且增進語音辨識率之方法
(2013-01-16)
白明憲
;
劉孆婷
;
桂振益
;
徐偉智
一種可消除雜音且增進語音辨識率之方法，包括以下步驟：提供二個以上的麥克風，用以接收至少二麥克風訊號；將麥克風訊號利用快速傅立葉轉換至頻率域，以取得其中之語音訊號與雜音訊號；計算語音訊號與雜音訊號之夾角，並使用一相位差演算法，進一步找出一耳間時間差；依據該夾角計算出耳間時間差之一閥值；依據耳間時間差與其閥值，使用一遮蔽法則，以取得語音訊號並去除雜音訊號；以及將語音訊號利用一反快速傅立葉轉換暨疊加模組轉至時間域輸出，藉此去除聲源中的雜音部分，以增進語音品質。
基於擴增實境與雲端計算之應用程式執行方法與系統
(2013-01-16)
陳烈武
;
曾煜棋
;
彭昱豪
一種創新的應用程式執行方法與系統，可利用動態影像或靜態照片來讓使用者取得欲通訊/查詢對象之識別帳號並觸發特定程式/網頁功能的人性化介面。本發明讓使用者不必自行輸入欲通訊對象的識別帳號，如E-Mail位址、MSN識別、Facebook識別、FTP IP、甚至是關鍵字等，只需一指拖曳人臉到應用程式圖示/網頁圖示上或將該應用程式圖示/網頁圖示拖曳到該人臉上，即可輕鬆完成執行應用程式/網站功能的過程，有效地降低使用者操作複雜度，並提供簡易的應用軟體與網站服務操作方法。
光感測元件及其製備方法
(2013-01-16)
陳智
;
劉健民
;
曾院介
本發明係有關於一種光感測元件及其製備方法，本發明之光感測元件具有極大蕭特基接面且其包括：一第一導電層；複數金屬奈米線，該每一金屬奈米線之一端係與該第一導電層連接，且該每一金屬奈米線之表面係覆有一半導體層，該半導體層之厚度係為1nm-20nm；以及一第二導電層，係對應該第一導電層而配置，該複數金屬奈米線係配置於該第一導電層與該第二導電層之間，且該第二導電層與該複數金屬奈米線表面之半導體層接觸；其中，該光感測元件係用於感測波長10nm-400nm之紫外光。
Weak antilocalization in topological insulator Bi2Te3 microflakes
(2013-01-16)
Chiu, Shao-Pin
;
Lin, Juhn-Jong
;
電子物理學系
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物理研究所
;
Department of Electrophysics
We have studied the carrier transport in two topological insulator (TI) Bi2Te3 microflakes between 0.3 and 10 K and under applied backgate voltages (V-BG). Logarithmic temperature dependent resistance corrections due to the two-dimensional electron-electron interaction effect in the presence of weak disorder were observed. The extracted Coulomb screening parameter is negative, which is in accord with the situation of strong spin-orbit scattering as is inherited in the TI materials. In particular, positive magnetoresistances (MRs) in the two-dimensional weak-antilocalization (WAL) effect were measured in low magnetic fields, which can be satisfactorily described by a multichannel-conduction model. Both at low temperatures of T < 1 K and under high positive VBG, signatures of the presence of two coherent conduction channels were observed, as indicated by an increase by a factor of approximate to 2 in the prefactor which characterizes the WAL MR magnitude. Our results are discussed in terms of the (likely) existence of the Dirac fermion surface states, in addition to the bulk states, in the three-dimensional TI Bi2Te3 material. DOI: 10.1103/PhysRevB.87.035122
Analysis of unequal error protection for LDPCA codes
(2013-01-17)
Sun, Y. -C.
;
Tsai, W. -J.
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資訊工程學系
;
Department of Computer Science
Unequal error protection extensions of low density parity check accumulate (UEP-LDPCA) codes are discussed and several potential applications are proposed. Two UEP-LDPCA schemes are analysed and code parameters are optimised using a density evolution algorithm. Simulation results show that the extensions have the significant unequal error protection property. This activates new directions for existing applications.
Enhanced photoactivity of Cu-deposited titanate nanotubes for removal of bisphenol A
(2013-01-17)
Doong, Ruey-an
;
Chang, Sue-min
;
Tsai, Chia-wei
;
環境工程研究所
;
Institute of Environmental Engineering
One-dimensional nanotubes are promising nanostructured materials for a wide variety of environmental applications. In this study, the Cu-deposited titanate nanotubes (TNTs) were fabricated using an alkaline hydrothermal method at 150 degrees C and then 0.5-2 wt% Cu(II) ions were photodeposited onto the calcined TNTs at 500 degrees C for enhanced photodegradation of bisphenol A (BPA) under illumination of 365 nm UV light. The as-synthesized TNTs showed tubular structures with the outer diameter and inter-layer spacing of 7-10 and 0.8 nm, respectively. The X-ray absorption near-edge spectral results provided a strong support on the partially structural change from layered trititanate to anatase TiO2 through the distortion of octahedral TiO6 unit at 500 degrees C and the production of mixture of CuO and Cu2O after photodeposition of Cu ions, resulting in the formation of Cu-deposited TiO2/TNT nanocomposites to enhance the photocatalytic activity. A nearly complete removal of BPA by the Cu-deposited TiO2/TNTs was observed, and the pseudo-first-order rate constants (k(obs)) for BPA photodegradation by Cu-deposited TiO2/TNTs at pH 7.0 were 1.8-5.2 and 4.3-12.7 times higher than those of pure Degussa P25 and ST01 TiO2, respectively. In addition, the k(obs) for BPA photodegradation reached the maximum value of 0.253 +/- 0.032 min(-1) at 1 wt% Cu(II). The X-ray photoelectron spectra showed that the ratio of Cu2O to total Cu increased from 3.2% in the dark to 35.2% after illumination of 365 nm UV light for 5 min. In addition, electron paramagnetic resonance results indicated that the copper ions could serve as the electron mediators to prolong the retention time of photo-generated radicals, resulting in the enhancement of photodegradation efficiency and rate of BPA by Cu-deposited TiO2/TNTs. (C) 2012 Elsevier B.V. All rights reserved.
Neutral-Fragmentation Paths of Methane Induced by Intense Ultrashort IR Laser Pulses: Ab Initio Molecular Orbital Approach
(2013-01-17)
Koseki, Shiro
;
Shimakura, Noriyuki
;
Teranishi, Yoshiaki
;
Lin, Sheng Hsien
;
Fujimura, Yuichi
Instantaneous (laser-field-dependent) potential energy curves leading to neutral fragmentations of methane were calculated at several laser intensities from 1.4 x 10(13) to 1.2 x 10(14) W/cm(2) (from 1.0 x 10(10) to 3.0 X 10(10) V/m) using ab initio molecular orbital (MO) methods to validate the observation of neutral fragmentations induced by intense femtosecond IR pulses (Kong et al. J. Chem. Phys. 2006, 125, 133320). Two fragmentation paths, CH2 + 2H and CH2 + H-2, in T-1(2) superexcited states that are located in the energy range of 12-16 eV were considered as the reaction paths because these states are responsible for Jahn-Teller distortion opening up reaction paths during ultrashort pulses. As field intensity increased, the low-lying excited (1)A(1) states originated from the Jahn-Teller T-1(2) states were substantially stabilized along the neutral-fragment path CH4 -> CH2 + 2H and were located below the ionization threshold. On the other hand, the low-lying excited B-1(1) states, which also originate from the Jahn-Teller T-1(2) states, were embedded on the ionized state along the dissociation path to CH2 + H-2. This indicates that ionic fragments, rather than neutral ones, are produced along the CH2 + H-2 path. The computational results support neutral fragmentations through superexcited states proposed by Kong et al.