Tsung-Lung Li

National Kaohsiung First University of Science and Technology, Kao-hsiung-shih, Kaohsiung, Taiwan

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Publications (14)11.84 Total impact

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    ABSTRACT: In this article, a course on high-frequency wireless communications systems is presented. With the 145-MHz baseband subsystem available from a prerequisite course, the present course emphasizes the design and implementation of the 2.45-GHz front-end subsystem as well as system integration issues. In this curriculum, the 2.45-GHz front-end subsystem includes only the antenna and the low-noise amplifier. Laboratory sessions are an essential part of the course. Successive completion of the laboratories automatically leads students to having a “working” 2.45-GHz wireless communications system. This course is beneficial to students who will pursue a career in wireless communication technology and related fields.
    IEEE Transactions on Education 01/2010; 53:631-637. · 0.95 Impact Factor
  • Ming-Huei Chen, Tsung-Lung Li
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    ABSTRACT: In this article, a curriculum on the construction and maintenance of a high-performance computing cluster for students in engineering and science is presented. Laboratory sessions are an important part of this curriculum. Successive completion of the laboratory sessions automatically leads the student group to a homemade full-functioned cluster. Students are encouraged as they see their computing cluster working at the end of the curriculum. This curriculum can be of benefit to the students who are involved with computationally intensive simulations. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 678–684, 2011
    Computer Applications in Engineering Education 05/2009; 19(4):678 - 684. · 0.33 Impact Factor
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    ABSTRACT: At the growth temperature at and above 700degC as well as C<sub>2</sub>H<sub>4</sub> flow rate of 20 seem,, carbon nanotubes (CNTs) were synthesized on the SiO<sub>2</sub> substrates dip-coated with Co acetate only. The fine dispersion of Co particles was caused by a strong interaction between metal acetate and SiO<sub>2</sub> support. Due to the high process (atmospheric) pressure, the reduced catalytic activity of Co could not assist CNT growth for the Co-Mo bimetallic catalysts on oxide surface. CNTs could not be synthesized with the addition of nitrogen to the carrier gas, either. It was inferred that the carrier gas of pure hydrogen is essential to inhibit the formation of cobalt oxides due to the trace oxygen in the atmospheric furnace and thus sustain the activity of Co particles. With the catalyst of 0.02 wt% Co acetate, highly selective growth of high-purity SWNTs was attained at the growth temperature at and above 800degC by atmospheric thermal CVD. The SWNT diameter measured by AFM confirmed the value determined from the RBM of Raman spectrum and Bandow's relationship.
    University/Government/Industry Micro/Nano Symposium, 2008. UGIM 2008. 17th Biennial; 08/2008
  • Tsung-Lung Li, Jyh-Hua Ting
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    ABSTRACT: The Fermi-level subband indices of single-wall carbon nanotubes (SWCNTs) are investigated by exploring the positions of graphene degenerate points relative to nanotubes subbands. By these algebraic methods, SWCNTs are naturally classified into eight types: two types for both metal-1 and -2; and four types for semiconductor. Using the general arguments of number theory, this classification scheme is, for the first time, shown to be exhaustive. The subbands indices are also given explicitly by formulae and algorithms readily applicable to computations.
    Physica B Condensed Matter 01/2007; 393(1):195-203. · 1.33 Impact Factor
  • Tsung-Lung Li, Jyh-Hua Ting, Bo-Zhi Yang
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    ABSTRACT: Conducting properties of suspended carbon nanotubes grown by thermal chemical vapor deposition (CVD) are investigated. The thermal CVD growth is performed at a temperature about 200 °C lower than usual with the intention to circumvent process integration issues posed by CVD growth at higher temperatures. The growth conditions are obtained by tuning the CVD gas flows so that there are yields of devices with a small number of nanotubes bridging the metal pads. Using these growth conditions, over 70 devices with sparse bridging nanotubes are obtained at 750 °C. These devices are used to characterize the conducting properties. It is found that the contact resistance of 1.5–5 MΩ can be attributed to the nanotube defect densities and the resulting loose nanotube-metal contacts. Furthermore, semiconductive devices are observed. Their transfer characteristics are explained by the Schottky barrier at the nanotube-metal interface. The noise of semiconductive devices observed at large bias may be due to quantum interference between crossed nanotubes.
    Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures 01/2007; 25(4):1221-.
  • Tsung-Lung Li, Jyh-Hua Ting, Chung-Yuan Kung
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    ABSTRACT: A parallelizable simulator of the chemical shrink process of nanolithography is developed to investigate the process dependence on material properties. The chemical shrink process model employed for the simulator includes the cross-linking reaction of the resolution enhancement of lithography assisted by chemical shrink (RELACS) material, the inhibitor deprotection reaction of the chemically amplified (CA) resist, and the photoacid diffusion and trapping in the CA resist and RELACS material. It is found that, in the descending order of their effectiveness on amount of shrinkage, the photoacid trapping and diffusion mechanisms of the RELACS are the most effective ones, the photoacid trapping mechanism of the CA resist is second, the photoacid diffusion mechanism of the CA resist and the cross-linking reaction of the RELACS are third, and the deprotection reaction of the CA resist is the least effective. The interpretations of the dependence of the shrinkage amounts on these mechanisms are also provided on the basis of the simulations.
    Japanese Journal of Applied Physics 01/2006; 45:7964-7974. · 1.07 Impact Factor
  • Jyh-Hua Ting, Tsung-Lung Li, Ying-Chi Hong
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    ABSTRACT: The purpose of this study is to investigate the effect of graphitization of carbon nanotube (CNT) films on their field emission efficiencies. CNT films were prepared by microwave plasma-enhanced chemical vapor deposition (MPCVD) method. Transmission electron microscopy images reveal the center hollowness and multiwalled structure of a CNT. The tip-growth mechanism of the CNTs prepared by MPCVD is confirmed by the nickel particles enclosed at the tips of the CNTs. The intensity ratio of IG/(ID+IG) under the Raman spectrum was defined to characterize the degree of graphitization of the CNTs. At any methane flow ratios [CH4/(H2+CH4)], the CNT graphitization increases with the microwave power. Also, the CNT graphitization increases with the CH4 flow ratio and begins to drop at the flow ratio of 15%. It is mainly attributed to the relative concentration of carbon radicals in the hydrocarbon-based plasma. Enhancement of the graphitization of CNT emitter array leads to the decrease of the threshold field and the increase of the field-controlled current density consistently. This consistency suggests that higher concentration of sp2 bonding enhances conductivity. Therefore, the field emission efficiency of the CNTs increases with the CNT graphitization. At the microwave power of 1200 W and the methane flow ratio of 15%, the graphitization intensity ratio is 0.637. The optimal threshold field and field-controlled current density at the field of 3 V/μm are 1.38 V/μm and 8.934 mA/cm2- ula>, respectively.
    Journal of vacuum science & technology. B, Microelectronics and nanometer structures: processing, measurement, and phenomena: an official journal of the American Vacuum Society 01/2006; 24(4). · 1.27 Impact Factor
  • Tsung-Lung Li, Jyh-Hua Ting
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    ABSTRACT: The temporal saturation effects of the critical dimensions of nanoscale contact holes are investigated by a two-dimensional reaction-diffusion simulator for the chemical shrink techniques of nanolithography. Models included with the simulator are the crosslinking reaction of water-soluble polymers and crosslinkers, the diffusion of photoacids, and the inactivation of photoacids. Within the the statistical errors of the experimental data, the simulation critical dimensions agree with the experiment for baking temperatures over 105°C and for all baking times. It is found that the temporal saturation of the contact holes' critical dimensions can be explained by the photoacid inactivating reaction included in the simulator.
    Japanese Journal of Applied Physics 01/2005; 44:6327-6331. · 1.07 Impact Factor
  • Tsung-Lung Li, Jyh-Hua Ting
    Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures 01/2005; 23(4).
  • Tsung-Lung Li, Jyh-Hua Ting
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    ABSTRACT: The effectiveness of reaction-diffusion mechanisms on the formation of nanoscale polymer films in the chemical shrink process is investigated by a two-dimensional model. The model includes three mechanisms: the catalytic cross-linking reaction of water-soluble polymers and cross-linkers, the diffusion of photoacids, and the trapping of photoacids by the cross-linked polymers. It is found that, although the cross-linking reaction is the vital mechanism for the chemical shrink process, it is much less effective on the formation of nanoscale polymer films than the photoacids diffusion and trapping mechanisms.
    Chemical Physics Letters 01/2005; 414(4):292-295. · 2.15 Impact Factor
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    ABSTRACT: We investigate the field emission property of carbon nanotubes (CNTs) prepared by microwave plasma enhanced chemical vapour deposition (MPCVD) method.
    Microprocesses and Nanotechnology Conference, 2003. Digest of Papers. 2003 International; 11/2003
  • Tsung-Lung Li, Jyh-Hua Ting
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    ABSTRACT: The time-dependent postexposure bake (TDPEB) simulator, previously reported to include the time dependence of parameters in the entire course of the postexposure bake (PEB) simulation, is used to simulate the PEB process with different combinations of bake times and pattern dimensions. Comparison of the results of simulation shows that the time dependence of the simulation is greater for shorter bake times.
    Japanese Journal of Applied Physics 01/2002; 41:79-80. · 1.07 Impact Factor
  • Tsung-Lung Li, Jyh-Hua Ting
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    ABSTRACT: A simulator is devised to investigate the effects of temperature-time history on the post-exposure bake of deep-UV resists based on a simple reaction-diffusion model whose reaction coefficients and diffusion coefficient are treated as temperature-dependent parameters over the entire course of the bake process. The temperature, in turn, is modeled by exponential functions with heating and cooling time constants. Because the reaction slows down as the bake process proceeds, the cooling stage has to be much longer than that for the heating. The optimal process condition determined from this simulation is the maintenance of the cooling/heating constant ratio between 20 and 30.
    Japanese Journal of Applied Physics 01/2001; 40. · 1.07 Impact Factor
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    ABSTRACT: Dispersed growth techniques are applied to grow carbon nanotubes between metal pads on silicon wafers. Process conditions are tuned to yield nanotube devices having only one multi-walled carbon nanotube connecting the metal pads. The nonlinear transfer characteristics of these devices are often accompanied with high impedance and low conduction current. These attributes can be utilized for a soft limiting circuit with impedance much higher than conventional silicon-based implementations.
    Applied Physics A 100(1):193-196. · 1.55 Impact Factor