Browsing by Issue Date, starting with "2007-02-19"

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Effect of Al-trace degradation on Joule heating during electromigration in flip-chip solder joints
(2007-02-19)
Liang, S. W.
;
Chiu, S. H.
;
Chen, Chih
;
材料科學與工程學系
;
Department of Materials Science and Engineering
This study investigates the mechanism for the abrupt increase in temperature at later stages of electromigration in flip-chip solder joints. It is found that electromigration also occurs in Al traces when stressed by 0.6 A at 100 degrees C. Three-dimensional thermoelectrical simulation by finite element analysis was carried out to simulate the temperature distribution in solder joints with and without degradation of the Al trace. It is found that the degradation of the Al trace has substantial effect on the Joule heating of solder joints. This model can explain the serious Joule heating effect in the later stages of electromigration. (c) 2007 American Institute of Physics.
Wavelength switching transition in quantum dot lasers
(2007-02-19)
Wang, Hsing-Yeh
;
Cheng, Hsu-Chieh
;
Lin, Sheng-Di
;
Lee, Chien-Ping
;
電子工程學系及電子研究所
Control and the selection of the ground state emission and/or the excited state emission of an InAs quantum dot laser have been demonstrated. By controlling the currents injected into each section of a two-section cavity, switching between the ground state emission and the excited state emission with a separation of 100 nm was achieved. With a constant total current, either ground state lasing (similar to 1.3 mu m), excited state lasing (similar to 1.2 mu m), or dual state lasing can be obtained simply by adjusting the current ratio between the two sections. (c) 2007 American Institute of Physics.
Double-pass high-gain low-noise EDFA over Sand C+L-bands by tunable fundamental-mode leakage loss
(2007-02-19)
Hung, Chi-Ming
;
Chen, Nan-Kuang
;
Lai, Yinchieh
;
Sien, Chi
;
光電工程學系
We demonstrate a high-gain low-noise double-pass tunable EDFA over S- and C+L-bands by discretely introducing fundamental-mode leakage loss in a 16-m-long standard C-band Er3+-doped fiber. The amplified spontaneous emission at the wavelengths of longer than 1530 nm can be substantially attenuated by the ASE suppressing filters to maintain high population inversion and to squeeze out the optical gain for S- band signals. When the filters are disabled, the gain bandwidth immediately returns back to the C+L-bands. Under S-band operation, a 37 dB small signal gain and a minimum 4.84 dB noise figure at 1486.9 nm are achieved with a 980 nm pump power of 154 mW. (c) 2007 Optical Society of America.
Micro actuated grating for multi-beam optical pickups
(2007-02-19)
Lee, Chi-Hung
;
Chiu, Yi
;
Shieh, Han-Ping D.
;
電控工程研究所
;
光電工程學系
A stress-induced curved polysilicon actuator with a grating is achieved for the application of recordable optical pickups, which have been realized on a single silicon chip using a two-layer poly-silicon and one-layer silicon nitride micro-machining process. Three diffracted beams with equal intensity in each order from the grating were generated while applying a voltage to the actuator. The switching between the single beam and multiple beams can be applied for writing data and reading data in the disc, respectively. (c) 2007 Optical Society of America.
Infrared spectra of C2H2 under jet-cooled and para-H-2 matrix conditions
(2007-02-19)
Lee, Ying-Chi
;
Venkatesan, V.
;
Lee, Yuan-Pern
;
Macko, P.
;
Didiriche, K.
In spectra of jet-cooled C2H2 recorded with an FTIR spectrometer, the v(5), v(4) + v(5), v(3) and v(2) + v(4) + v(5) bands all exhibit an intensity distribution corresponding to similar to 6 K for rotation, with no evidence of nuclear spin conversion. Spectra of C2H2 isolated in solid p-H-2 show no evidence of rotation of C2H2. The strong interaction between v(3) and v(2) + v(4) + v(5) in the gas phase is diminished in solid p-H-2. Lines associated with dimer, trimer and tetramer of C2H2 are identified. Spectral features characteristic of solid state acetylene are observed under jet-cooled conditions. (c) 2007 Elsevier B.V. All rights reserved.
Use of Si+ pre-ion-implantation on Si substrate to enhance the strain relaxation of the GexSi1-x metamorphic buffer layer for the growth of Ge layer on Si substrate
(2007-02-19)
Hsieh, Y. C.
;
Chang, E. Y.
;
Luo, G. L.
;
Pilkuhn, M. H.
;
Tang, S. S.
Si+ pre-ion-implantation combined with a GexSi1-x metamorphic buffer structure for the growth of Ge layer on Si substrate is proposed. Enhanced strain relaxation of the GexSi1-x metamorphic buffer layer on Si substrate was achieved due to the introduction of the point defects by heavy dose Si+ pre-ion-implantation. Because of the strain relaxation enhancement and the interface blocking of the dislocations in the GexSi1-x metamorphic buffer structure, the total thickness of the buffer layers was only 0.45 mu m. No cross-hatch pattern was observed on the Ge surface and the dislocation density for the top Ge film was only 7.6x10(6) cm(-2). (c) 2007 American Institute of Physics.
Effect of ZnSe partial capping on the ripening dynamics of CdSe quantum dots
(2007-02-19)
Lai, Y. J.
;
Yang, C. S.
;
Chen, W. K.
;
Lee, M. C.
;
Chang, W. H.
The ripening dynamics of CdSe quantum dots (QDs) partially capped with ZnSe layer are investigated. Atomic force microscopy (AFM) images show that the ripening of QDs is dramatically accelerated by depositing a ZnSe partial capping layer. The driving force of ripening enhancement is attributed to the increasing strain energy with capping thickness. For a ZnSe partial capping layer of below 3 ML, photoluminescence exhibits a clear redshift with increasing ZnSe monolayers. It is attributed to the size of the CdSe QD increases with ZnSe partial capping, in a manner that is consistent with the results of the AFM study. (c) 2007 American Institute of Physics.
Post flight analysis of the surface plasmon resonance enhanced photoelastic modulated ellipsometry
(2007-02-20)
Chao, Yu-Faye
;
Han, Chien-Yuan
;
光電工程學系
;
Department of Photonics
A total internal reflection ellipsometer equipped with a photoelastic modulator (PEM) is installed to investigate the chemical activation and antibody immobilization process on thin gold films. We set up two detection channels in this configuration: one for real-time monitoring with a data rate of 1 set per second, and the other for post flight analysis with a data rate of 25,000 sets per second. More detailed information has been obtained through the post flight analysis technique during the chemical activation process. This surface plasmon resonance enhanced PEM ellipsometry provides higher sensitivity and temporal resolution. It is feasible to resolve a faster reaction such as chemical reaction or protein folding by the post flight analysis technique. (c) 2006 Elsevier B.V. All rights reserved.
Three-dimensional modeling of small-scale processes in the upper boundary layer bounded by a dynamic ocean surface
(2007-02-20)
Tsai, Wu-ting
;
Hung, Li-ping
;
土木工程學系
;
Department of Civil Engineering
[1] We present a numerical model for simulating boundary-layer turbulence bounded by a dynamic ocean surface and driven by wind stresses. The nonlinear boundary conditions are satisfied on the freely moving surface exactly without any approximation. The time-dependent physical space is mapped onto a rectangular computational domain where the momentum equations are integrated in time for the velocity field and the solenoidal condition is satisfied by solving the transformed pressure Poisson equation. The developed model is validated with a progressive gravity wave and with a gravity-capillary wave. The model capabilities for resolving surface waves of various length scales, ranging from the gravity waves to the capillary ripples, and the nonlinear interactions among the waves are highlighted by simulating the evolution of two-dimensional short-crested gravity-capillary waves and the development of a gravity wave train into crescent patterns. The potential applicability of the model for studying the wind-driven aqueous near-surface layer is then demonstrated. The simulation results reveal fine surface structures, including microscale breaking waves and streamwise velocity streaks, which have been observed in the laboratory and field experiments.
Illumination system for wire bonding inspection
(2007-02-20)
Perng, Der-Baau
;
Chou, Cheng-Chuan
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Lee, Shu-Ming
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工業工程與管理學系
;
Department of Industrial Engineering and Management
A novel lighting system was devised for 3D defect inspection in the wire bonding process. Gold wires of 20 mu m in diameter were bonded to connect the integrated circuit (IC) chip with the substrate. Bonding wire defects can be classified as 2D type and 3D type. The 2D-type defects include missed, shifted, or shorted wires. These defects can be inspected from a 2D top-view image of the wire. The 3D-type bonding wire defects are sagging wires, and are difficult to inspect from a 2D top-view image. A structured lighting system was designed and developed to facilitate all 2D-type and 3D-type defect inspection. The devised lighting system can be programmed to turn the structured LEDs on or off independently. Experiments show that the devised illumination system is effective for wire bonding inspection and will be valuable for further applications.
影像式物件追蹤方法
(2007-02-21)
傅智銘
;
黃仲陵
本發明提出一種影像式物件追蹤方法，其特徵為兩階段式的獲取物件區域機率，第一階段是以像素特徵為基礎，第二階段是以候選區塊物件形狀機率為基礎來追蹤與獲取物件區域。本發明可以將系統初始化的動作標準化運用在不同的環境下，且利用運算量低的無標籤追蹤技術，可以有效得到動態軌跡，而不需藉助手套或標記的輔助，用以得到物件的區域與軌跡，作為輔助性人機介面。
Monte Carlo simulations of stress relaxation of entanglement-free Fraenkel chains. II. Nonlinear polymer viscoelasticity
(2007-02-21)
Lin, Y. -H.
;
Das, A. K.
;
應用化學系
;
Department of Applied Chemistry
The nonlinear viscoelastic behavior of the Fraenkel-chain model is studied with respect to the constitutive equation of the Rouse model. Distinctly different from the results of the Rouse model, the Fraenkel-chain model gives the following characteristic nonlinear behavior: (a) The two distinct dynamic modes in the relaxation modulus G(S)(t,lambda)-as observed in the linear region reported in Paper I [Y.-H. Lin and A. K. Das, J. Chem. Phys. 126, 074902 (2007), preceding paper]-or in the first normal-stress difference function G(Psi 1)(t,lambda) are shown to have different strain dependences: strain hardening for the fast mode and strain softening for the slow mode. (b) The Lodge-Meissner relation G(S)(t,lambda)=G(Psi 1)(t,lambda) holds over the whole time range, which has been shown both analytically and by simulation. (c) The second normal-stress difference is nonzero, being positive in the fast-mode region and negative in the slow-mode region. The comparisons between orientation and stress for all tensor components consistently confirm the strong correlation of the slow mode as well as its entropic nature with the segmental-orientation anisotropy as shown in the linear region studied in Paper I. A consequence of this correlation is the applicability of the stress-optical rule in the slow-mode region. This also leads to the expectation that the damping function h(lambda)=G(S)(t,lambda)/G(S)(t,lambda -> 0) and the ratio between the first and second normal-stress differences, N-2(t,lambda)/N-1(t,lambda), are described by the orientation tensor which has the same form as that given by Doi and Edwards [J. Chem. Soc. Faraday Trans. 2 74, 1789 (1978); 74, 1802 (1978)] with independent-alignment approximation for an entangled system. The similarity between the slow mode of an entanglement-free Fraenkel-chain system and the terminal mode of an entangled polymer system as observed in the comparison of theory, simulation, and experiment suggests that the close correlation of the entropic nature of the mode with the orientation anisotropy-as of the Fraenkel segment or the primitive step in the Doi-Edwards theory-is a generally valid physical concept in polymer viscoelasticity. (c) 2007 American Institute of Physics.
Mobility asymmetry in InGaAs/InAlAs heterostructures with InAs quantum wires
(2007-02-21)
Lin, Z. C.
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Hsieh, W. H.
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Lee, C. P.
;
Suen, Y. W.
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電子工程學系及電子研究所
Strong asymmetry of electron mobility in InGaAs/InAlAs heterostructures (lattice matched to InP) with the presence of InAs quantum wires was observed. Self-assembled InAs quantum wires, embedded in an InGaAs matrix close to the hetero-interface, has a strong effect in electron conduction in the interface channel. The low temperature mobility for electrons moving parallel to the quantum wires is much higher than that of electrons moving perpendicular to the wires. The asymmetry in mobility is attributed to the difference in scattering cross section of the quantum wires in these two directions.
資料錯誤率量測裝置及其偽隨機碼產生器
(2007-02-21)
陳巍仁
;
黃冠勝
一種資料錯誤率量測裝置及其偽隨機碼產生器。此資料錯誤率量測裝置包括發送端偽隨機碼產生器、主偽隨機碼產生器、僕偽隨機碼產生器、比較器以及計數單元。發送端偽隨機碼產生器產生平行N位元之原偽隨機碼(N為大於1之整數)，其中待測物接收原偽隨機碼後輸出平行N位元之待測碼。主偽隨機碼產生器產生平行N位元之主偽隨機碼，以及僕偽隨機碼產生器產生平行N位元之僕偽隨機碼。比較器接收並比較待測碼、主偽隨機碼以及僕偽隨機碼是否相同，以及輸出比較結果。計數單元耦接至比較器，用以依據比較結果計數資料錯誤次數。
Monte Carlo simulations of stress relaxation of entanglement-free Fraenkel chains. I. Linear polymer viscoelasticity
(2007-02-21)
Lin, Y. -H.
;
Das, A. K.
;
應用化學系
;
Department of Applied Chemistry
Shear stress relaxation modulus G(S)(t) curves of entanglement-free Fraenkel chains have been calculated using Monte Carlo simulations based on the Langevin equation, carrying out both in the equilibrium state and following the application of a step shear deformation. While the fluctuation-dissipation theorem is perfectly demonstrated in the Rouse-chain model, a quasiversion of the fluctuation-dissipation theorem is observed in the Fraenkel-chain model. In both types of simulations on the Fraenkel-chain model, two distinct modes of dynamics emerge in G(S)(t), giving a line shape similar to that typically observed experimentally. Analyses show that the fast mode arises from the segment-tension fluctuations or reflects the relaxation of the segment tension created by segments being stretched by the applied step strain-an energetic-interactions-driven process-while the slow mode arises from the fluctuations in segmental orientation or represents the randomization of the segmental-orientation anisotropy induced by the step deformation-an entropy-driven process. Furthermore, it is demonstrated that the slow mode is well described by the Rouse theory in all aspects: the magnitude of modulus, the line shape of the relaxation curve, and the number-of-beads (N) dependence of the relaxation times. In other words, one Fraenkel segment substituting for one Rouse segment, it has been shown that the entropic-force constant on each segment is not a required element to give rise to the Rouse modes of motion, which describe the relaxation modulus of an entanglement-free polymer over the long-time region very well. This conclusion provides an explanation resolving a long-standing fundamental paradox in the success of Rouse-segment-based molecular theories for polymer viscoelasticity-namely, the paradox between the Rouse segment size being of the same order of magnitude as that of the Kuhn segment (each Fraenkel segment with a large force constant H-F can be regarded as basically equivalent to a Kuhn segment) and the meaning of the Rouse segment as defined in the Rouse-chain model. The general agreement observed in the comparison of the simulation and experimental results indicates that the Fraenkel-chain model, while being still relatively simple, has captured the key element in energetic interactions-the rigidity on the segment-in a polymer system. (c) 2007 American Institute of Physics.
以茶葉黑色素預防及改善乙醯胺酚（acetaminophen）毒性
(2007-02-21)
黃國華
本發明係關於以茶葉黑色素預防及/或改善乙醯胺酚(acetaminophen)毒性之方法，其包括於攝取過量乙醯胺酚之前或同時對哺乳動物投與有效量之茶葉黑色素；一種可用於預防或降低乙醯胺酚毒性之含有茶葉黑色素之醫藥組成物，以及含有茶葉黑色素與乙醯胺酚之醫藥組成物。
INTERCONNECT OF GROUP III- V SEMICONDUCTOR DEVICE AND FABRICATION METHOD FOR MAKING THE SAME
(2007-02-22)
Lee, Cheng-Shih
;
Chang, Edward Yi
;
Chang, Huang-Choung
An interconnect of the group III-V semiconductor device and the fabrication method for making the same are described. The interconnect includes a first adhesion layer, a diffusion barrier layer for preventing the copper from diffusing, a second adhesion layer and a copper wire line. Because a stacked-layer structure of the first adhesion layer/diffusion barrier layer/second adhesion layer is located between the copper wire line and the group III-V semiconductor device, the adhesion between the diffusion barrier layer and other materials is improved. Therefore, the yield of the device is increased.
Complicated phase behavior and ionic conductivities of PVP-co-PMMA-based polymer electrolytes
(2007-02-23)
Chiu, Chun-Yi
;
Yen, Ying-Jie
;
Kuo, Shlao-Wei
;
Chen, Hsien-Wei
;
Chang, Feng-Chih
We have used DSC, FTIR spectroscopy, and ac impedance techniques to investigate the interactions that occur within complexes of poly(vinylpyrrolidone-co-methyl methacrylate) (PVP-co-PMMA) and lithium perchlorate (LiClO(4)) as well as these systems' phase behavior and ionic conductivities. The presence of MMA moieties in the PVP-co-PMMA random copolymer has an inert diluent effect that reduces the degree of self-association of the PVP molecules and causes a negative deviation in the glass transition temperature (T,). In the binary LiClO(4)/PVP blends, the presence of a small amount of LiClO(4) reduces the strong dipole-dipole interactions within PVP and leads to a lower T(g). Further addition of LiClO(4) increases T(g) as a result of ion-dipole interactions between LiClO(4) and PVP. In LiClO(4)/PVP-co-PMMA blend systems, for which the three individual systems-the PVP-co-PMMA copolymer and the LiClO(4)/PVP and LiClO(4)/PMMA blends-are miscible at all compositional ratios, a phase-separated loop exists at certain compositions due to a complicated series of interactions among the LiClO(4), PVP and PMMA units. The PMMA-rich component in the PVP-co-PMMA copolymer tends to be excluded, and this phenomenon results in phase separation. At a LiClO(4) content of 20 wt% salt, the maximum ionic conductivity occurred for a LiClO(4)/VP57 blend (i.e., 57 mol% VP units in the PVP-co-PMMA copolymer). (c) 2007 Elsevier Ltd. All rights reserved.
Scatterings of massive string states from D-brane and their linear relations at high energies
(2007-02-26)
Chan, Chuan-Tsung
;
Lee, Jen-Chi
;
Yang, Yi
;
電子物理學系
;
Department of Electrophysics
We study scatterings of bosonic massive closed string states at arbitrary mass levels from D-brane. We discover that all the scattering amplitudes can be expressed in terms of the generalized hypergeometric function F-3(2) with special arguments, which terminates to a finite sum and, as a result, the whole scattering amplitudes consistently reduce to the usual beta function. For the simple case of D-particle, we explicitly calculate high-energy limits of a series of the above scattering amplitudes for arbitrary mass levels, and derive infinite linear relations among them for each fixed mass level. The ratios of these high-energy scattering amplitudes are found to be consistent with the decoupling of high-energy zero-norm states of our previous works. (c) 2006 Elsevier B.V. All rights reserved.
Evanescent-field optical amplifiers and lasers
(2007-02-27)
Chen
;
Nan-Kuang
;
Chi
;
Sien
;
Tseng
An optical amplifier and a laser generator based on the fiber side-polished technology having a high pumping efficiency, a low noise figure and a small footprint are provided in this application. The optical amplifier and the laser, which have a very long effective interaction length in conjunction with highly doped Erbium glass attached to its surface and an addition of a slanted fiber grating inscribed in the guiding core at the polished region can spatially separate the signal and pump power to simultaneously improve the pumping efficiency and optimize the penetrated depth of the signal evanescent-field. The spontaneous emission is kept from being amplified and therefore a high quality amplified signal is produced.