Browsing by Author "Chen, CW"

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3-disjoint gamma interconnection networks
(2003-05-15)
Chen, CW
;
Lu, NP
;
Chung, CP
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose a new multistage interconnection network, called 3-disjoint gamma interconnection network (3DGIN). The 3DGIN is a modified gamma interconnection network that provides 3-disjoint paths to tolerate two switch or link faults between any source and destination pairs. The 3DGIN has lower hardware cost than GIN; furthermore, the routing and rerouting tags to generate 3-disjoint paths can be obtained in O(logN) time. To show the advantage features of 3DGIN, we also make a comparison between the gamma-related networks, the GIN, enhanced IADM, and 3DGIN. (C) 2002 Elsevier Science Inc. All rights reserved.
A design approach to the multi-objective facility layout problem
(1999-03-20)
Chen, CW
;
Sha, DY
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
A new multi-objective heuristic algorithm for resolving the facility layout problem is presented in this paper. It incorporates qualitative and quantitative objectives and resolves the problem of inconsistent scales and different measurement units. We consider suboptimal solutions since optimal methods are computationally unfeasible to large layout problems. In this paper, we develop the dominant index (DI) and incorporate it in our heuristic algorithm to guarantee the quality of proposed solutions. Moreover, a new measure of solution quality, dominant probability (D-p), is offered to determine the probability that one layout is better than the others. Computational results show that our proposed heuristic algorithm is an efficient method for obtaining good-quality solutions.
A novel approach of fabricating germanium nanocrystals for nonvolatile memory application
(2004-01-01)
Chang, TC
;
Yan, ST
;
Liu, PT
;
Chen, CW
;
Lin, SH
A nonvolatile memory device embedded with Ge nanocrystal dots is fabricated by the thermal oxidation of Si0.8Ge0.2 combined with a rapid thermal annealing at 950degreesC in N-2 gas. The tunnel oxide in the nonvolatile memory is controlled to be 4.5 nm thick and embedded with 5.5 nm Ge nanocrystals. A low operating voltage, 5 V, is implemented and a significant threshold-voltage shift, 0.42 V, is observed. When the electrons are trapped in the Ge nanocrystals, the effect of Coulomb blockade prevents the injection and storage of more electrons and decreases the leakage current. Also, the retention characteristics are tested to be robust. (C) 2003 The Electrochemical Society.
Anisotropic O 2p-Mn 3d unoccupied states in La1-xMnO3: an X-ray absorption spectroscopy study
(2002-02-01)
Lin, JY
;
Chen, CW
;
Liu, YC
;
Liu, SJ
;
Wu, KH
We have studied La1-xMnO3 thin films, which show the metal-insulator transition similar to La1-xCaxMnO3. The transport and magnetic properties are measured, X-ray absorption spectroscopy is employed to investigate the electronic structure. Surprisingly, the electronic structure of La1-xMnO3 shows large anisotropy. Our results suggest that La1-xMnO3 is unique among manganites. (C) 2002 Elsevier Science B.V. All rights reserved.
Application and robustness design of fuzzy controller for resonant and chaotic systems with external disturbance
(2005-06-01)
Hsiao, FH
;
Chiang, WL
;
Chen, CW
;
Xu, SD
;
Wu, SL
A robustness design of fuzzy control via model-based approach is proposed in this paper to overcome the effect of approximation error between nonlinear system and Takagi-Sugcno (T-S) fuzzy model. T-S fuzz model is used to model the resonant and chaotic systems and the parallel distributed compensation (PDC) is employed to determine structures of fuzzy controllers. Linear matrix inequality (LMI) based design problems are utilized to find common definite matrices P and feedback gains K satisfying stability conditions derived in terms of Lyapunov direct method. Finally, the effectiveness and the feasibility of the proposed controller design method is demonstrated through numerical simulations on the chaotic and resonant systems
Augmented stereo panoramas
(2006)
Chen, CW
;
Chan, LW
;
Tsai, YP
;
Hung, YP
;
資訊工程學系
Panoramas and object movies are popular image-based techniques for modeling and rendering 3D scenes and objects. In this paper, we present a method which allows the authors of virtual exhibition systems to produce an augmented stereo panorama by interactively integrating stereo object movies into a stereo panorama. When navigating in the augmented stereo panorama with a stereoscopic display, the user can directly browse the stereo object movies that he is interested in. With augmented stereo panoramas, the user can enjoy more persuasive interaction with better depth perception. To our best knowledge, this paper is the first work to integrate stereoscopic image-based scenes with stereo object movies.
CMP of low-k methylsilsesquiazane with oxygen plasma treatment for multilevel interconnect applications
(2004)
Chang, TC
;
Tsai, TM
;
Liu, PT
;
Chen, CW
;
Yan, ST
The effect of oxygen plasma treatment on methylsilsesquiazane (MSZ) dielectric was investigated for chemical mechanical planarization (CMP) process. Oxygen plasma treatment was implemented before CMP. Experimental results have shown that the polishing rate of MSZ film with O-2 plasma pretreatment is increased as much as two order of magnitude more than that of MSZ without O-2 plasma pretreatment. Moreover, the electrical properties of post-CMP MSZ are close to those of an as-cured MSZ. These results indicate that the modified surfaces resulting from O-2 plasma treatment increase the polishing rate of MSZ. After polishing, the MSZ film still maintains a low-k quality. (C) 2004 The Electrochemical Society.
CMP of ultra low-k material porous-polysilazane (PPSZ) for interconnect applications
(2004-01-30)
Chang, TC
;
Tsai, TM
;
Liu, PT
;
Chen, CW
;
Yan, ST
In this article, we investigated the impact of chemical mechanical polishing (CMP) on an ultra low dielectric constant (ultra low-k) material Porous-Polysilazane (PPSZ) with slurries of metal polishing during interconnect manufacture process. Since the CMP processing of metals such as TaN and Cu are inevitable steps for interconnect fabrication, we have utilized two types of slurries (marked as TaN and Cu slurries) to evaluate their effects on the dielectric properties of PPSZ films. Electrical and material analyses have shown surface planarity and dielectric properties of PPSZ films will not be degraded during these metal CMP processes. This indicates that the ultra low-k PPSZ films are promising for inter-level dielectric (ILD) applications in ultra large-scale integrated circuits (ULSI) technology. (C) 2003 Elsevier B.V. All rights reserved.
Cu-penetration induced breakdown mechanism for a-SiCN
(2004-12-22)
Chen, CW
;
Liu, PT
;
Chang, TC
;
Yang, JH
;
Tsai, TM
We have investigated the leakage mechanism of amorphous SiCN (a-SiCN) films after bias-temperature-stress (BTS) with Cu electrode. The leakage current became very large and breakdown due to the Cu ions penetration after strict BTS condition. The distribution profile of Cu penetration was depicted by SIMS spectrum. It is apparent that Cu ions penetrated into the a-SiCN film and even reached to the interface between a-SiCN/Si due to BTS. The Cu ions existing in a-SiCN would be taken as trap states and could enhance the carriers to transport. The main characteristics of post-breakdown a-SiCN followed the space-charge-limited current (SCLC) mechanism at 298 K. With decreasing the temperature to 100 K, the Fowler-Nordheim tunneling dominated the conduction in medium fields. However, electrons obeyed the SCLC again in high fields (>3.3 MV/cm) at 100 K. We purpose a physical model to interpret the leakage mechanism of breakdown a-SiCN films due to Cu ions. (C) 2004 Elsevier B.V. All rights reserved.
Damage effect of fluorine implantation on PECVD alpha-SiOC barrier dielectric
(2005-08-01)
Yang, FM
;
Chang, TC
;
Liu, PT
;
Chen, CW
;
Tai, YH
in this work the dielectric properties of plasma enhanced chemical vapor deposited (PECVD) amorphous SiOC (alpha-SiOC) films with various concentrations of oxygen are investigated for the barrier dielectric application. Experimental results show after fluorine (F) ion implanted into alpha-SiOC film, the leakage current in carbide film is increased due to the generation of trap centers. Afterwards, the traps can be effectively repaired after thermal annealing, leading to the decrease of leakage current further. From the extraction of the current-voltage (J-E) characteristics, the conducting mechanism of the leakage current obeys the Poole-Frenkel type behavior for intrinsic, F-implanted and thermally annealed samples. Also, the barrier height of the F-implanted and thermally annealed samples are extracted and exhibits a higher value than that of the intrinsic sample. (c) 2005 Elsevier B.V. All rights reserved.
Deep sub-micron strained Si0.85Ge0.15 channel p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) with ultra-thin N2O-annealed SiN gate dielectric
(2005)
Chen, CW
;
Chien, CH
;
Chen, YC
;
Hsu, SL
;
Chang, CY
We have investigated the electrical characteristics of strained Si0.85Ge0.15 channel p-channel metal-oxide-semiconductor field effect transistors (pMOSFETs) with ultra-thin N2O-annealed SiN gate dielectric. We have found that the thickness of SiGe channel has a great impact on the device characteristics. With controlling the SiGe layer thickness thinner than 15 nm, the device depict a subthreshold swing of 68 mV/A, the interface state density of 1 x 10(11) eV(-1) cm(-2), acceptable junction leakage, and more than 50% hole mobility improvement with respect to the Si channel device. Therefore, high quality interface between the gate dielectric and the strained SiGe channel can be achieved by using the N2O-annealed SiN gate dielectric.
Designing a disjoint paths interconnection network with fault tolerance and collision solving
(2005-10-01)
Chen, CW
;
Chung, CP
;
資訊工程學系
;
Department of Computer Science
In fault-tolerant interconnection designs, many prior researches suggest good use of disjoint paths to improve the reliability of interconnection networks. Although disjoint paths increase reliability, they always cost the throughput penalty. To address the problems of both performance and fault-tolerant capability, the following issues should be carefully considered: (1) guarantee of at least two disjoint paths, (2) easy rerouting between disjoint paths, (3) keep low rerouting hops, (4) solve the occurrences of packets' collision. In this paper, we consider these issues to design a fault-tolerant network called CSMIN (Combining Switches Multistage Interconnection Network). CSMIN provides two disjoint paths to guarantee one fault-tolerant and can dynamically reroute packets between these two paths to solve the collision situation. In other words, to switch packets between these two disjoint paths easily, CSMIN causes these two disjoint paths to have regular distances at each stage. Accordingly, a packet can be dynamically sent to the other disjoint path if it encounters a faulty or busy element. In addition, CSMIN presents low rerouting hops (an average of one rerouting hop) to maintain a low collision ratio. From the simulation result, CSMIN performs with a better arrival ratio than Gamma and other related disjoint paths networks do.
Dielectric characteristics of low-permittivity silicate using electron beam direct patterning for intermetal dielectric applications
(2003-11-17)
Liu, PT
;
Chang, TC
;
Tsai, TM
;
Lin, ZW
;
Chen, CW
A direct patterning technology of low-permittivity silicate-based polymer is investigated with electron-beam lithography for multilevel interconnections. The smallest feature size of 60 nm for damascene lines can be directly patterned in the silicate film. In this direct patterning, dielectric regions exposed by electron beam are crosslinked and form desirable patterns, while the others are dissolvable in an aqueous solution containing 2.38% tetramethylammonium hydroxide. With an optimum condition of electron-beam lithography, the electron-beam-irradiated silicate exhibits superior dielectric properties than that of the furnace-cured silicate film, due to minimizing the break of Si-H bonds and moisture uptake. The explanation is in agreement with the analyses of Fourier transform infrared spectroscopy and thermal desorption spectroscopy. (C) 2003 American Institute of Physics.
Direct Patterning of low-k hydrogen silsesquioxane using X-ray exposure technology
(2003-05-01)
Chang, TC
;
Tsai, TM
;
Liu, PT
;
Mor, YS
;
Chen, CW
An inorganic low-k material, hydrogen silsesquioxane (HSQ), patterned directly using X-ray exposure technology was investigated. In conventional integrated circuit integration processes, photoresist (PR) stripping with O-2 plasma and wet chemical stripper are inevitable steps. However, dielectric degradation often occurs when low-k dielectrics undergo PR stripping processes. To overcome the integration issue X-ray direct patterning is proposed. In this technology, the dielectric regions illuminated by X-ray are cross-linked and form desired patterns, while the regions without X-ray illumination are dissolvable in the solvent of HSQ solution. An optical microscope image of an HSQ linear pattern was demonstrated for the first time to verify process feasibility. (C) 2003 The Electrochemical Society.
Direct Patterning of low-k hydrogen silsesquioxane using X-ray exposure technology (vol 6, pg G69, 2003)
(2003-07-01)
Chang, TC
;
Tsai, TM
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Liu, PT
;
Mor, YS
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Chen, CW
Effective repair to ultra-low-k dielectric material (k-2.0) by hexamethyidisilazane treatment
(2002-07-01)
Mor, YS
;
Chang, TC
;
Liu, PT
;
Tsai, TM
;
Chen, CW
O-2 plasma ashing is commonly used to remove photoresist. The effect of O-2 plasma ashing on the porous organosilicate glass (CH3SiO1.5)(n), one of the spin-on materials, is investigated. O2 plasma can oxidize the methyl groups in porous organosilicate glass (POSG), which leads to the formation of Si-OH groups. The hydrophilic Si-OH groups will induce moisture uptake so that electrical degradation will occur in POSG film. Pure hexamethyldisilazane (HMDS) vapor (100% HMDS) can react with the Si-OH groups in POSG film. It converts hydrophilic Si-OH groups into hydrophobic Si-O-Si(CH3)(3) groups against moisture uptake. The leakage current density decreases by a factor of 2-3 and the dielectric constant decreases from 3.62 to 2.4 when O-2 plasma-damaged POSG undergoes HMDS treatment at 80degreesC for 15 min. Therefore, HMDS treatment is the effective technique to repair the electrical degradation to POSG film during photoresist stripping processing. (C) 2002 American Vacuum Society.
Effective strategy for porous organosilicate to suppress oxygen ashing damage
(2002-03-01)
Liu, PT
;
Chang, TC
;
Mor, YS
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Chen, CW
;
Tsai, TM
Photoresist stripping with oxygen plasma ashing destroys numerous functional groups in porous organosilicate glasses (OSGs), This impact makes the porous OSG relatively hydrophilic and causes low-k dielectric degradation, To mitigate these issues, various strategies are investigated to enhance oxygen plasma resistance of the porous OSG. These include physical and chemical procedures. Both structural and electrical analyses are used to determine their efficiency. In addition, an optimum prescription that consists of H, plasma and chemical trimethylchlorosilane treatment is developed in this work. The enhancement of oxygen plasma resistance can provide the porous OSG for practical application in the multilevel interconnection. (C) 2002 The Electrochemical Society.
Effectiveness of NH3 plasma treatment in preventing wet stripper damage to low-k hydrogen silsesquioxane (HSQ)
(2001-12-01)
Chang, TC
;
Mor, YS
;
Liu, PT
;
Tsai, TM
;
Chen, CW
Wet stripper is commonly used to remove photoresist in IC integration processing. However, the high alkalinity of the wet stripper solution often leads to the hydrolysis of hydrogen silsesquioxane (HSQ) film and induces water uptake. As a result, both the leakage current and dielectric constant of HSQ increase. In this study, NH3 plasma treatment was applied to the HSQ film to form a thin nitrogen-containing layer on the HSQ surface and prevents the hydrolysis of HSQ during photoresist stripping. Dielectric degradation can be prevented by NH3 plasma treatment.
Effects of oxygen plasma ashing on barrier dielectric SiCN film
(2005)
Chen, CW
;
Chang, TC
;
Liu, PT
;
Tsai, TM
;
Tseng, TY
Effects of oxygen plasma ashing on barrier dielectric SiCN films have been studied for various ashing conditions. According to X-ray photoelectron spectra analyses, Si-O-2 bonds appear at the surface of SiCN film after O-2 plasma ashing. The formation of the oxidized layer, SiOxCN, at the surface of the SiCN film effectively reduces the leakage current as a consequence. The leakage conduction of the SiCN films has been investigated to be Schottky emission at the fields between 0.4 and 1.2 MV/cm. Also, the increase of Schottky barrier height between SiCN and the metal is calculated to be 42 meV after O-2 plasma ashing. (C) 2004 The Electrochemical Society.
Effects of postdeposition annealing on the characteristics of HfOxNy dielectrics on germanium and silicon substrates
(2006)
Cheng, CC
;
Chien, CH
;
Chen, CW
;
Hsu, SL
;
Yang, CH
We have systematically investigated the impact that postdeposition annealing (PDA) has on the physical and electrical properties of HfOxNy thin films sputtered on Ge and Si substrates. These two substrates display contrasting metal-oxide-semiconductor characteristics that we attribute to the different compositions of their interface layers (ILs). We observed an increased GeO2 incorporation into the HfOxNy dielectric and severe volatilization of the IL on Ge after higher PDA processing. These undesired phenomena in the HfOxNy/Ge gate stacks may be responsible for their different electrical properties with respect to those of the HfOxNy/Si gate stacks, i.e., a further scaling of the capacitance-equivalent thickness, a significant presence of fixed positive charges and electron-trapping sites, and a degradation of dielectric reliability. In addition, the anomalous low-frequency-like behavior of the high-frequency capacitance-voltage curves in inversion for the Ge capacitors was predicted from theoretical calculations. (c) 2006 The Electrochemical Society.