Browsing by Author "Lin, YC"

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2.4 V-operated enhancement mode PHEMT with 32 dBm output power and 61 % power efficenciecy
(2001)
Chen, SH
;
Chang, EY
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Lin, YC
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材料科學與工程學系
;
Department of Materials Science and Engineering
A 2.4 V operated enhancement-mode pseudormorphic high electron mobility transistors (E-PHEMTs) with high output power and power-added-efficiency (PAE) have been developed. With optimally designed epitaxial structure and gate recess process, the E-PHEMT shows high power performance and high power gain. Under 2.4 V bias at 1.9 GHz, the E-PHEMT shows maximum output power of 32.25 dBm and maximum power-added efficiency of 61.45% with linear power gain of 13.93 dB when the device was tuned for maximum output power match. When tuned for maximum output power added efficiency, the E-PHEMT can achieve a maximum PAE of 78.51%. The developed E-PHEMT with superior power performance is one of the candidates for power amplifiers used for 2.4 V-operated 3G wireless communication system.
2.4 V-operated enhancement-mode power PHEMTs for personal handy-phone system application
(2001)
Chen, SH
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Chang, EY
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Lin, YC
;
Lee, CS
;
友訊交大聯合研發中心
Enhacement-mode pseudomorphic high electron mobility transistors (E-PHEMTs) were developed for low voltage wireless communication applications. Under drain bias of 3.6 V, the device delivered a high output power density of 265.25 mW/mm (29.5dBm) with a power-added-efficiency (PAE) of 50.54 %. Under 1.9GHz pi/4-shifted quadrature phase shift keying(QPSK) modulation signal, the 3.36 mm devices meet personal handy-phone system (PHS) specification at an output power level of 22.42 dB with PAE of 35.12% under 2.4 V drain bias. The E-PHEMTs developed are adequate for low-voltage-operated PHS application.
A back-to-back micromirror device for optical add/drop multiplexer applications
(2003)
Lin, YC
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Chiou, JC
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電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, a back-to-back micromirror device fabricated through surface-micromachining and flip chip packaging technologies is developed for optical add/drop multiplexer applications. Pre-stressed beams were designed to elevate micromirror devices after the release and thermal heat-treatment processes. Torsion flexure structure design provides a reliable rotation degree of freedom for micromirror devices. A mechanical stopper was bonded using flip chip packaging on the top of micromirror devices to constrain the popped-up micromirror to obtain precise deflecting angle. Preliminary experiments had demonstrated the feasibility of the micromirror devices.
A high power enhancement-mode pseudomorphic high electron mobility transistor with 2.5 W output power and 64.5 % efficiency at 3 V
(2002)
Chen, SH
;
Chang, EY
;
Lin, YC
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材料科學與工程學系
;
Department of Materials Science and Engineering
A 3-V operated enhancement-mode pseudomorphic high electron mobility transistor (E-PHEMT) with high output power and high efficiency has been developed. The E-PHEMT has total gate width of 20 mm and gate length. of 0.5 mum. When the power performance was evaluated at 1.9 GHz, the E-PHEMT shows a saturation output power of 34.1 dBm (2.57 W) with power-added efficiency (PAE) of 64.5 % and power gain of 10.2 dB at 3 V bias. The linear gain under this testing condition is 14.9 dB. The E-PHEMTs developed have excellent power performance and are suitable for power amplifier application for cellular handsets.
A low noise composite-channel metamorphic HEMT for wireless communication applications
(2003)
Lu, CY
;
Chen, KS
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Lee, HM
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Chang, EY
;
Chen, SH
A composite-channel Metamorphic high electron mobility transistor (MHEMT) was developed for low noise high linearity application. The MHEMT was grown by Molecular Beam Epitaxy (MBE) on GaAs substrates with InAlAs graded buffer. The composite-channel layers in the MHEMT include a top In0.55Ga0.45As layer, a middle In0.67Ga0.33As layer, and a bottom In0.55Ga0.45As layer. The design of this structure provides better electron confinement in the channel with less impact ionization as compared to conventional dual delta doped MHEMTs. This results in devices with higher linearity and drain to gate voltage as compared to the conventional metamorphic HEMTs. The 0.25x160 mum(2) device with the novel channel structure exhibits a maximum frequency of oscillation f(max) of 290 GHz and a current gain cut-off frequency f(t) of 110 GHz. The noise figure of the device at 6 GHz is 0.23 dB and the associated gain was 15.06 dB. The IP3 of the device at 6 GHz is 19.67 dBm. The composite channel metamorphic HEMT shows great potential for high linearity and low noise application at high frequencies.
A metamorphic high electron-mobitity transistor with reflowed submicron T-Gate for high-speed optoelectronics applications
(2003)
Lien, YC
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Chang, EY
;
Chu, LX
;
Chang, HC
;
Lee, CS
A metamorphic high electron-mobility transistor (HEMT) manufactured with reflowed submicron T-gate using E-beam lithography for high-speed optoelectronics applications is developed. The In0.53Al0.47As/InGaAs HEMT uses InxAl1-xAs as the buffer layer between GaAs substrate and the InP lattice-matched HEMT structure. The T-gate developed has a gate length of 0.1 mum. The fabricated metamorphic HEMT has a saturation drain current of 280mA/mrn and a transconductance of 840mS/mm at V-DS=1.2V Noise figure for 160 mum gate-width device is less than 1 dB and the associated gain is up to 14dB at 18GHz. The device demonstrates a cut-off frequency f(T) of 150GHz and a maximum frequency f(MAX) up to 350GHz. The metamorphic HEMT developed has the potential for high-speed optoelectronics applications.
A micromirror device with tilt and piston motions
(1999)
Chiou, JC
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Lin, YC
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電控工程研究所
;
Institute of Electrical and Control Engineering
A newly developed micromirror device that possesses two rotational (tilt) and one displacement (piston) degrees of freedom has been designed and fabricated by using surface micromachining technology. The device consists of a micromirror, four vertical thermal-actuator arrays and four torsion bars that connect the mirror and the actuator. The vertical thermal actuator has the capability to elevate from its origin position. To demonstrate the feasibility of the vertical thermal actuator, various layouts and sizes has been designed. The present device was fabricated through the Multi-User MEMS process (MUMPs). When the controlled signal is applied to any two adjacent thermal-actuator arrays of the device, the remain two thermal actuator arrays and torsion bars will act as the supporting beams that allow the micromirror to experience rolling or pitching motion. On the other hand, by applying controlled signals to all four thermal-actuator arrays synchronously, the micromirror would elevate vertically. Note that different rolling or pitching angle of the micromirror can be archived by designing the locations of the torsion bars with vertical thermal actuators. Through the process, a compact, extremely light in weight, potentially low cost, and operating in very low voltage (<10V) micromirror device with various applications can be obtained.
A novel capacitance control design of tunable capacitor using multiple electrostatic driving electrodes
(2001)
Chiou, JC
;
Lin, YC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A novel control design method that is capable of linearly electrostatic driving a tunable capacitor is proposed in this paper. By extending the derivation of electrostatic theory and elastic theory in constructing the tunable capacitor, the nonlinear relationship between applied voltages and displacement (air gap) between two parallel plates of the capacitor is obtained. To suppress the nonlinearity so that the gap between the capacitor can vary linearly with the applied voltage, a control design method based on the variation of the multi-rectangular electrodes and applied voltages is proposed. By varying the number of rectangular electrodes that are evenly divided according to the size of the upper plate of the capacitor, the working space of the tunable capacitor with nonlinear characteristics is obtained. With this working space, linear control design method based on fixed or linearly varied applied voltages can be used to determine the number of the multi-rectangular electrodes such that stepping effect of the tunable capacitor can be achieved. Examples are used to demonstrate the feasibility of the present control design. Simulation results indicated that the linear control design method matched closely with the analytical analysis.
A novel current memory circuit for AMOLEDs
(2004-06-01)
Lin, YC
;
Shieh, HPD
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光電工程學系
;
Department of Photonics
A novel switched-current (SI) memory circuit with improved accuracy and operating frequency for active-matrix organic light-emitting displays (AMOLEDs) was developed. The proposed SI memory, constructed from current memory structure, can not only reduce the influence of charge-injection without using-larger storage capacitor, but also realize the significant amount of speed up by means of small storage capacitor. Furthermore, the capability of copying the current signal is achieved without relying on the matching of device characteristics. The proposed SI memory circuit was implemented by low temperature poly-silicon technology and is suitable for current driving scheme-based high-resolution AMOLED applications.
A novel current-scaling a-Si : H TFTs pixel electrode circuit for AM-OLEDs
(2005-06-01)
Lin, YC
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Shieh, HPD
;
Kanicki, J
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光電工程學系
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Department of Photonics
Hydrogenated amorphous silicon thin-film transistor (a-Si:H TFT) pixel electrode circuit with a function of current scaling is proposed for active-matrix organic light-emitting displays (AM-OLEDs). In contrast to the conventional current mirror pixel electrode circuit, in this circuit a high data-to-organic light-emitting device (OLED) current ratio can be achieved, without increasing the a-Si:H TFT size, by using a cascade structure of storage capacitors. Moreover, the proposed circuit can compensate for the variations of TFT threshold voltage. Simulation results, based on a-Si:H TFT and OLED experimental data, showed that a data-to-OLED current ratio larger than 10 and a fast pixel programming time can be accomplished with the proposed circuit.
A tilting micromirror with well-controlled digital angle through constrained lever structure
(2004)
Chiou, JC
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Kuo, CF
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Lin, YC
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電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, a tilting micromirror device that can achieve designed angle is proposed. A lever structure, driven by electrostatic actuators, was used to enlarge tilting angle. To obtain precise deflecting angle, the lever structure is constrained by the substrate. By applying a voltage, the electrostatic actuators drive the lever down to the substrate such that the micromirror device on the opposite side of the lever structure could be lifted. PolyMUMPs process was used to fabricate proposed micromirror devices. The actuators are simulated to investigate characteristics of the micromirror devices. Experimental results had indicated that the micromirror device could reach 10-degree tilting angle with 80V driving signal with 6.4% relative error compared to designed model.
Adsorption and desorption characteristics of semiconductor volatile organic compounds on the thermal swing honeycomb zeolite concentrator
(2003-11-01)
Chang, FT
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Lin, YC
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Bai, HL
;
Pei, BS
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環境工程研究所
The use of a honeycomb zeolite concentrator and an oxidation process is one of the most popular methods demonstrated to control volatile organic compound (VOCs) emissions from waste gases in semiconductor manufacturing plants. This study attempts to characterize the performance of a concentrator in terms of the removal efficiencies of semiconductor VOCs (isopropyl alcohol [IPA], acetone, propylene glycol methyl ether [PGME], and propylene glycol monomethyl ether acetate [PGMEA]) under several parameters that govern the actual operations. Experimental results indicated that at inlet temperatures of under 40 degreesC and a relative humidity of under 80%, the removal efficiency of a zeolite concentrator can be maintained well over 90%. The optimal rotation speed of the concentrator is between 3 and 4.5 rph in this study. The optimal rotation speed increases with the VOCs inlet concentration. Furthermore, reducing the concentration ratio helps to increase the removal efficiency, but it also increases the incineration cost. With reference to competitive adsorption, PGMEA and PGME are more easily adsorbed on a zeolite concentrator than are IPA and acetone because of their high boiling points and molecular weights.
An early vision-based snake model for ultrasound image segmentation
(2000-02-01)
Chen, CM
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Lu, HHS
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Lin, YC
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統計學研究所
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Institute of Statistics
Due to the speckles and the ill-defined edges of the object of interest, the classic image-segmentation techniques are usually ineffective in segmenting ultrasound (US) images. In this paper, we present a new algorithm for segmenting general US images that is composed of two major techniques; namely, the early-vision model and the discrete-snake model, By simulating human early vision, the early-vision model can capture both grey-scale and textural edges while the speckle noise is suppressed. By performing deformation only on the peaks of the distance map, the discrete-snake model promises better noise immunity and more accurate convergence. Moreover, the constraint for most conventional snake models that the initial contour needs to be located very close to the actual boundary has been relaxed substantially. The performance of the proposed snake model has been shown to be comparable to manual delineation and superior to that of the gradient vector flow (GVF) snake model. (C) 2000 World Federation for Ultrasound in Medicine & Biology.
An efficient algorithm for sorting by block-interchanges and its application to the evolution of vibrio species
(2005)
Lin, YC
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Lu, CL
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Chang, HY
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Tang, CY
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生物科技學系
In the study of genome rearrangement, the block-interchanges have been proposed recently as a new kind of global rearrangement events affecting a genome by swapping two nonintersecting segments of any length. The so-called block-interchange distance problem, which is equivalent to the sorting by block-interchange problem, is to find a minimum series of block-interchanges for transforming one chromosome into another. In this paper, we study this problem by considering the circular chromosomes and propose a O(deltan) time algorithm for solving it by making use of permutation groups in algebra, where n is the length of the circular chromosome and 3 is the minimum number of block-interchanges required for the transformation, which can be calculated in O(n) time in advance. Moreover, we obtain analogous results by extending our algorithm to linear chromosomes. Finally, we have implemented our algorithm and applied it to the circular genomic sequences of three human vibrio pathogens for predicting their evolutionary relationships. Consequently, our experimental results coincide with the previous ones obtained by others using a different comparative genomics approach, which implies that the block-interchange events seem to play a significant role in the evolution of vibrio species.
Applying hexagonal nanostructured zeolite particles for acetone removal
(2005-06-01)
Lin, YC
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Bai, HL
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Chang, CL
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環境工程研究所
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Institute of Environmental Engineering
This study examines the performance of a new adsorbent, hexagonal nanostructured zeolite particles (HNZP) for acetone adsorption and compares the results with that of commercial mobil synthetic zeolite-5 (ZSM-5) type zeolite. The HNZP is a pure siliceous adsorbent with different values of pore diameter and surface area being adjustable by the manufacturing condition. The results indicate that a slight increase in the average pore diameter (d) of HNZP from 2 to 2.5 nm leads to an increase in the acetone adsorption capacity, although its surface area is decreased, in which case (d = 2.5 nm) the adsorption capacity of fresh HNZP is better than that of ZSM-5 zeolite. Even for the fresh HNZP (d = 2 nm) of which the adsorption capacity is less than that of the ZSM-5 zeolite at relative humidity (RH) of 0%, its adsorption capacity is not deteriorated after repeated regeneration, but the adsorption capacity of regenerated ZSM-5 zeolite decays markedly. Thus, after only one regeneration, the adsorption capacity of HNZP (d = 2 nm) becomes better than that of the ZSM-5 zeolite. The decrease in the adsorption capacity of regenerated ZSM-5 zeolite might be because of its aluminum content that catalyzes the acetone into coke and, thus, blocks the adsorption sites. Furthermore, result on the moisture effect shows that because the pure siliceous HNZP was more hydrophobic than the ZSM-5 zeolite, the acetone adsorption efficiency of fresh HNZP (d = 2 nm) is better than that of ZSM-5 zeolite at RH = 50%.
Barrier properties of very thin Ta and TaN layers against copper diffusion
(1998-07-01)
Wang, MT
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Lin, YC
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Chen, MC
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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
Diffusion barrier properties of very thin sputtered Ta and reactively sputtered TaN films used as a barrier layer between Cu and Si substrates were investigated using electrical measurement and materials analysis. The Cu/Ta/p(+)-n junction diodes with the Ta barrier of 5, 10, and 25 nm thicknesses were able to sustain a 30 min thermal annealing at temperatures up to 450, 500, and 550 degrees C, respectively, without causing degradation to the device's electrical characteristics. The barrier capability of Ta layer can be effectively improved by incorporation of nitrogen in the Ta film using reactive sputtering technique. For the Cu/TaN/p(+)-n junction diodes with the TaN barrier of 5,10, and 25 nm thicknesses, thermal stability was able to reach 500, 600, and 700 degrees C, respectively. We found that failure of the very thin Ta and TaN barriers was not related to Ta silicidation at the barrier/Si interface. Failure of the barrier layer is presumably due to Cu diffusion through the barrier layer during the process of thermal annealing via local defects, such as grain boundaries and stress-induced weak points.
Closed-loop fuzzy control of torsional micromirror with multiple electrostatic electrodes
(2002)
Chiou, JC
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Lin, YC
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Wu, SD
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電控工程研究所
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Institute of Electrical and Control Engineering
Comparison between immersion-based and toboggan-based watershed image segmentation
(2006-03-01)
Lin, YC
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Tsai, YP
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Hung, YP
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Shih, ZC
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資訊工程學系
Watershed segmentation has recently become a popular tool for image segmentation. There are two approaches to implementing watershed segmentation: immersion approach and toboggan simulation. Conceptually, the immersion approach can be viewed as an approach that starts from low altitude to high altitude and the toboggan approach as an approach that starts from high altitude to low altitude. The former seemed to be more popular recently (e.g., Vincent and Soille), but the latter had its own supporters (e.g., Mortensen and Barrett). It was not clear whether the two approaches could lead to exactly the same segmentation result and which approach was more efficient. In this paper, we present two "order-invariant" algorithms for watershed segmentation, one based on the immersion approach and the other on the toboggan approach. By introducing a special RIDGE label to achieve the property of order-invariance, we find that the two conceptually opposite approaches can indeed obtain the same segmentation result. When running on a Pentium-III PC, both of our algorithms require only less than 1130 s for a 256 x 256,image and 115 s for a 512 x 512 image, on average. What is more surprising is that the toboggan algorithm, which is less well known in the computer vision community, turns out to run faster than immersion algorithm for almost all the test images we have used, especially when the image is large, say, 512 x 512 or larger. This paper also gives some explanation as to Why the toboggan algorithm can be more efficient in most cases.
Composite-channel metamorphic high electron mobility transistor for low-noise and high-linearity applications
(2004-07-01)
Chang, EY
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Lin, YC
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Chen, GJ
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Lee, HM
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Huang, GW
A metamorphic high-electron-mobility transistor (MHEMT) with In0.55Ga0.45As/In0.67Ga0.33As/In0.55Ga0.45As composite channel layers was developed for low-noise and high-linearity applications. The use of: a composite channel results in high electron mobility and good confinement of electrons in the channel region which are the desired characteristics of low-noise and high-linearity devices. The noise figure of the 0.25 x 160 mum(2) devices is 0.23 dB with 15.06 dB associated gain, and the output third-order intercept point (IP3) is 18.67 dBm at 6 GHz. The device shows great potential for high-linearity and low-noise applications at high frequencies.
Control of VOCs emissions by condenser pre-treatment in a semiconductor fab
(2005-04-11)
Lin, YC
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Chang, FT
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Bai, HL
;
Pei, BS
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環境工程研究所
The performance of a modified design of local condensers to pre-treat a variety of volatile organic compounds (VOCs) emitted from the stripping process of a semiconductor fab was tested in this study. The reaction temperature of the condensers was controlled at around 10 degrees C, it is relatively higher than the traditional condenser reaction temperature. Both VOCs and water vapors were condensed and formed liquid films. This resulted in an enhancement of the VOCs removals, especially for VOCs of high boiling points or solubility. This can help to prevent the follow up zeolite concentrator from damage. The performance of the integrated system of condenser/zeolite concentrator could, therefore, remain highly efficient for a longer operation time. Its annualized cost would also be lower than installing the zeolite concentrator only. (c) 2005 Elsevier B.V. All rights reserved.