Browsing by Issue Date, starting with "2005-09-29"

Now showing 1 - 20 of 65960

Singlemode InAs quantum dot photonic crystal VCSELs
(2005-09-29)
Yang, HPD
;
Chang, YH
;
Lai, FI
;
Yu, HC
;
Hsu, YJ
An InAs quantum dot photonic crystal vertical-cavity surface-emitting laser (QD PhC-VCSEL) for fibre-optic applications is first demonstrated. Single fundamental mode CW output power of 0.2 mW has been achieved in the 1300 nm range, with a threshold current of 4.75 mA. Side-mode suppression ratio larger than 40 dB has been observed over the entire thermally limited operation range.
Spin Hall effect on edge magnetization and electric conductance of a 2D semiconductor strip
(2005-09-30)
Mal'shukov, AG
;
Wang, LY
;
Chu, CS
;
Chao, KA
;
電子物理學系
The intrinsic spin Hall effect on spin accumulation and electric conductance in a diffusive regime of a 2D electron gas has been studied for a 2D strip of a finite width. It is shown that the spin polarization near the flanks of the strip, as well as the electric current in the longitudinal direction, exhibit damped oscillations as a function of the width and strength of the Dresselhaus spin-orbit interaction. Cubic terms of this interaction are crucial for spin accumulation near the edges. As expected, no effect on the spin accumulation and electric conductance have been found in case of Rashba spin-orbit interaction.
Defending against spoofed DDoS attacks with path fingerprint
(2005-10-01)
Lee, FY
;
Shieh, S
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose anew scheme, called ANTI D, for detecting and filtering DDoS attacks which use spoofed packets to circumvent the conventional intrusion detection schemes. The proposed anti-DDoS scheme intends to complement, rather than replace conventional schemes. By embedding in each IP packet a unique path fingerprint that represents the route an IP packet has traversed, ANTID is able to distinguish IP packets that traverse different Internet paths. In ANTID, a server maintains for each of its communicating clients the mapping from the client's IP address to the corresponding path fingerprint. The construction and renewal of these mappings is performed in an on-demand fashion that helps to reduce the cost of maintenance. With presence of the mapping table, the onset of a spoofed DDoS attack can be detected by observing a surge of spoofed packets. Consequently, spoofed attack packets are filtered so as to sustain the quality of protected Internet services. ANTID is lightweight, robust, and incrementally deployable. Our experiment results showed that the proposed scheme can detect 99.95% spoofed IP packets and can discard them with little collateral damage to legitimate clients. It also showed that the higher the aggregated attack rate is, the sooner the attack can be detected. (C) 2005 Elsevier Ltd. All rights reserved.
Effects of channel width on electrical characteristics of polysilicon TFTs with multiple nanowire channels
(2005-10-01)
Wu, YC
;
Chang, TC
;
Liu, PT
;
Chen, CS
;
Tu, CH
This brief studies the electrical characteristics of a series of polysilicon thin-film transistors (poly-Si TFTs) with different numbers of multiple channels of various widths, with lightly doped drain (LDD) structures. The nanoscale TFT with ten 67-nm-wide split channels (M10) has superior and more uniform electrical characteristics than other TFTs. Additionally, experimental results reveal that the electrical performance of proposed TFTs enhances with each channel width decreasing, yielding a profile from a single-gate to tri-gate structure.
Electrochemical study on screen-printed carbon electrodes with modification by iron nanoparticles in Fe(CN)(6)(4-/3-) redox system
(2005-10-01)
Lee, SH
;
Fang, HY
;
Chen, WC
;
Lin, HM
;
Chang, CA
The remarkable enhancement of electron transfer on screen-printed carbon electrodes (SPCEs) with modification by iron nanoparticles (Fe-nano), coupled with Fe(CN)(6)(4-/3-) redox species, was characterized with an increase of electroactive area (A(ea)) at electrode surface together with a decrease of heterogeneous. electron transfer rate constant (k degrees) in the system. Hence, Fe-nano-Fe(CN)(6)(3-) SPCEs with deposition of glucose oxidase (GOD) demonstrated a higher sensitivity to various glucose concentrations than Fe(CN)(6)(3-)/GOD-deposited SPCEs. In addition, an inhibited diffusion current from cyclic voltammograms was also observed with an increase in redox concentration and complicated the estimation of A(ea). Further analysis by the electrochemical impedance method, it was shown that this effect might be resulted from the electrode surface blocking by the products of activated complex decomposition.
Novel single-poly EEPROM with damascene control-gate structure
(2005-10-01)
Sung, HC
;
Lei, TF
;
Hsu, TH
;
Wang, SW
;
Kao, YC
A novel single-poly EEPROM using damascene control gate (CG) structure is presented in this letter. The CG is tungsten (W) line made by a damascene process, and intergate dielectric is Al2O3 grown by atomic layer deposition (ALD). The program and erase mechanism is the same as the one for traditional stacked-gate cell, which uses the channel hot electron injection for programming and Fowler-Nordheim tunneling for channel erasing. With the high dielectric constant (K) property of Al2O3, we can perform the program and erase function with a voltage less than 6.5 V, which can be handled by 3.3 V devices instead of traditional high voltage devices. In the process compatibility aspect, this new cell needs only two extra masking steps over the standard CMOS process, and the high-kappa material is deposited in the back-end metallization steps without the contamination concerns on the front-end process. Therefore, this new technology is suitable for embedded application. In this letter, the good cell performance is demonstrated; such as, fast programming/erasing, good endurance and data retention.
Tunable deep-ultraviolet source generated by scattering off adiabatically prepared Raman coherence in hydrogen gas
(2005-10-01)
Chen, WJ
;
Kung, AH
;
光電工程學系
;
Department of Photonics
We demonstrate a tunable deep-ultraviolet coherent source generated by the beating of a tunable UV laser and strongly driven vibrational Raman coherence in hydrogen. The total energy conversion efficiency reaches a maximum of 50% at the phase side of the Raman coherence. The generated spectrum of Raman sidebands tunes with the input and extends from 435 to 146 nm for an input at 282 nm. (c) 2005 Optical Society of America.
Special section on papers presented at IDMC '05 - Introduction
(2005-10-01)
Shieh, HPD
;
Wu, IW
;
顯示科技研究所
;
Institute of Display
小孩
(2005-10-01)
管管
小孩
(2005-10-01)
管管
Optimal design of CMOS pseudoactive pixel sensor (PAPS) structure for low-dark-current and large-array-size imager applications
(2005-10-01)
Shih, YC
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, a pixel structure called the optimal pseudoactive pixel sensor (OPAPS) is proposed and analyzed for the applications of CMOS imagers. The shared zero-biased-buffer in the pixel is used to suppress both dark current of photodiode and leakage current of pixel switches by keeping both biases of photodiode and parasitic pn junctions in the pixel bus at zero voltage or near zero voltage. The factor of photocurrent-to-dark-current ratio per pixel area (PDRPA) is defined to characterize the performance of the OPAPS structure. It is found that a zero-biased-buffer shared by four pixels can achieve the highest PDRPA. In addition, the column sampling circuits and output correlated double sampling circuits are also used to suppress fixed-pattern noise, clock feedthrough noise, and channel charge injection. An experimental chip of the proposed OPAPS CMOS imager with the format of 352 x 288 (CIF) has been designed and fabricated by using 0.25-mu m single-poly-five-level-metal (1P5M) N-well CMOS process. In the fabricated CMOS imager, one shared zero-biased-buffer is used for four pixels where the PDRPA is equal to 47.29 mu m(-2). The fabricated OPAPS CMOS imager has a pixel size of 8.2 x 8.2 mu m, fill factor of 42%, and chip size of 3630 x 3390 mu m. Moreover, the measured maximum frame rate is 30 frames/s and the dark current is 82 pA/cm(2). Additionally, the measured optical dynamic range is 65 dB. It is found that the proposed OPAPS structure has lower dark current and higher optical dynamic range as compared with the active pixel sensor (APS) and the conventional passive pixel sensor (PPS). Thus, the proposed OPAPS structure has high potential for the applications of high-quality and large-array-size CMOS imagers.
從代理理論的角度探討董事會特性、股權結構與負債之關聯性
(2005-10-01)
洪榮華
;
陳香如
;
柯璟瑩
;
Jung-Hua Hung
;
Hsiang-Ju Chen
本文從代理問題的角度，檢視董事會特性及股權結構與負債之關聯性，同時探討負債、內部人持股、機構人持股與股利政策等監督機制之替代效果，並進一步驗證集團與非集團企業之差異性。以上市公司為對象，資料從1995到2001年，透過聯立模型以3SLS實證發現：(1)內部人持股、機構人持股與負債間互呈顯著正相關，符合管理據守、利益衝突與策略合力假說；其他股權結構、董事會特性變數與負債間則多不顯著，顯示國內公司治理尚有很大的進步空間。(2)股利與負債政策間互呈顯著負相關，兩者為替代的監督機制。(3)集團與非集團樣本可能因融資方式與條件不同，而有不同的融資考量。
An automatic pin identification method for a three-phase DC brushless motor
(2005-10-01)
Wang, SJ
;
Cheng, CC
;
Lin, SK
;
Ju, JJ
;
Huang, DR
The pin identification is to find the definition of each connecting pin of a three-phase brushless motor. The 11 pins of the motor can be distinguished into three groups by a simple resistance measurement method. An automatic method has two steps. In the first step, the motor is in an open-circuited mode; and the individual pins of the windings are identified by comparing back electromotive forces. A special integral is defined and used to match Hall signal pins with the Hall sensors. The polarity of each pair of the Hall signal pins is determined by the second step of a standstill method. The proposed method is illustrated and verified by an experiment.
Fabrication and characterization of In0.25Ga0.75N/GaN multiple quantum wells embedded in nanorods
(2005-10-01)
Hsueh, TH
;
Sheu, JK
;
Huang, HW
;
Chang, YH
;
Ou-Yang, MC
ln(0.25)Ga(0.75)N/GaN multiple quantum wells embedded in nanorods with diameters of 60-100nm were fabricated by inductively coupled plasma reactive ion etching with Cl-2/Ar plasma. The strong optical emission of the nanorods, observed by micro-photoluminescence measurement at 80 K, reveals a large blue shift of about 90meV and an increase in photoluminescence intensity density of more than 17-fold, compared with that of the as-grown wafer under the same excitation power density of 80W/cm(2). These nanostructures have a high potential for application in efficient GaN-based vertical cavity emitters.
Broadband C- plus L-band double-ring fiber baser based on a two-stage hybrid amplifier
(2005-10-01)
Yeh, CH
;
Cheng, BC
;
Chen, CY
;
Chi, S
;
光電工程學系
A stable and wavelength-tunable C- plus L-band fiber double-ring laser, which uses a two-stage hybrid amplifier with a semiconductor optical amplifier and an erbium-cloped fiber amplifier, has been proposed and experimentally demonstrated. Based on the double-ring configuration, the proposed fiber ring laser exhibits more stable output wavelengths and powers than the single-ring laser. A wide tunable range of 1540 to 1620 nm, a side-mode suppression ratio (SMSR) of > 31.2 dB/0.05 nm over a wide tuning range from 1550 to 1612 nm, and an output power of > 2 dBm over the operation range of 1546 to 1608 nm have been achieved. (c) 2005 Society of Photo-Optical Instrumentation Engineers.
A system dynamics model of the semiconductor industry development in Taiwan
(2005-10-01)
Chen, JH
;
Jan, TS
;
管理科學系
;
Department of Management Science
Taiwan has become the fourth largest semiconductor manufacturer worldwide within only 25 years. Taiwan's success in developing its semiconductor industry has been widely recognized. Building a semiconductor industry in a developing country is costly, risky, and requires long-term accumulations of capital, technology, human resources, and production capacity. The development process depends on environmental interactions, which should be studied in an integrated and holistic manner. Using system dynamics methodology, this study analyses the development experience of the Taiwanese semiconductor industry, in order to provide better insight into the long-term industrial development process. The study also simulates the proposed model in one historical setting and two future scenarios. Implications for the development of the semiconductor industry in Taiwan and other Asian countries are discussed.
小孩
(2005-10-01)
管管
Using optical Fabry-Perot devices for a wavelength-tunable S-band erbium-doped fiber ring laser with single-frequency operation
(2005-10-01)
Yeh, CH
;
Chien, HC
;
Cheng, BC
;
Lee, CC
;
Chi, S
We have proposed and experimentally demonstrated a stabilized and tunable S-band erbium-doped fiber ring laser by using a Fabry-Perot laser diode (FPLD) and a fiber Fabry-Perot filter inside the ring cavity. Due to the bandwidth limitation of the FPLD, the effective operating range of the proposed laser is confined to 1490.28 to 1521.22 nm with a tuning step of 0.08 nm. A side-mode suppression ratio of > 39.1 dB at 0.05 nm and an output power of > 0.4 dBm can be achieved while this laser is tuned from 1490.28 to 1510.27 nm. Zero output wavelength variation and output power fluctuation <= 0.03 dB have also been obtained. (c) 2005 Society of Photo-Optical Instrumentation Engineers.
Very high-density (23 fF/mu m(2)) RF MIM capacitors using high-k TaTiO as the dielectric
(2005-10-01)
Chiang, KC
;
Lai, CH
;
Chin, A
;
Wang, TJ
;
Chiu, HF
A very high density of 23 fF/mu m(2) has been measured in RF metal-insulator-metal (MIM) capacitors which use high-kappa TaTiO as the dielectric. In addition, the devices show a small reduction of 1.8% in the capacitance, from 100 kHz to 10 GHz. Together with these characteristics the MIM capacitors show low leakage currents and a small voltage-dependence of capacitance at 1 GHz. These TaTiO MINI capacitors should be useful for precision RF circuits.
In-process functional testing of pixel circuit in AM-OLEDs
(2005-10-01)
Lin, YC
;
Shieh, HPD
;
顯示科技研究所
;
Institute of Display
This paper presents a functional testing scheme using a two-thin-film-transistor (TFT) pixel circuit of an active-matrix organic light-emitting display (AM-OLED). This pixel circuit and the co-operative electrical testing scheme can not only evaluate the characteristics of each TFT, but also determine the location of line and point defects in the TFT array. Information on defects can be. used in a unique repair system that cutting and repairing these defects. Furthermore, the functional testing scheme can be applied as a part of yield management of the AM-OLED array process.