Browsing by Issue Date, starting with "2002-12-02"

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The novel pattern method of low-k hybrid-organic-siloxane-polymer film using X-ray exposure
(2002-12-02)
Chang, TC
;
Tsai, TM
;
Liu, PT
;
Mor, YS
;
Chen, CW
An organic low dielectric constant (low-k) material, hybrid-organic-siloxane-polymer. (HOSP), is integrated into multilevel interconnection using X-ray exposure technology. In conventional IC integration processes, photoresist (PR) stripping with O-2 plasma and wet chemical stripper is an inevitable step. However, dielectric degradation often occurs when low-k dielectrics undergo the PR stripping process. This limits the application of incorporating low-k material into semiconductor fabrication. In order to overcome the integration issue, a novel pattern method, X-ray direct patterning is proposed. In this technology, the dielectric regions illuminated by X-ray will be cross-linked, forming the desired patterns. At the same time, the regions without X-ray illumination are dissolvable in a solvent of HOSP film. Direct-patterning processes have several advantages: (1) they do not need PR to define patterns; thereby the damage from PR stripping can be eliminated, (2) the complex etching on low-k dielectrics can be eliminated, (3) the process steps are simplified. In this work, we will investigate the dielectric properties of HOSP film with X-ray curing for the first time. Additionally, a scanning electron microscope image of circle pattern was made to verify the process practicability. (C) 2002 Elsevier Science B.V. All rights reserved.
Effects of nitridation of silicon and repeated spike heating on the electrical properties of SrTiO3 gate dielectrics
(2002-12-02)
Liu, CY
;
Lue, HT
;
Tseng, TY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Electrical properties of SrTiO3 (STO) gate dielectrics on Si substrates grown by rf-magnetron sputtering were studied. We employed the surface nitridation and repeated spike heating to improve the interfacial properties of STO/Si. The nitrogen was moderately incorporated at the interface by first growing a thin SiON layer and then removing this sacrificial layer before growing STO gate dielectric. The experimental results indicate that this nitridation treatment may retard the formation of thin interfacial layer during the high-temperature growth of STO gate dielectric and consequently decrease the equivalent oxide thickness (EOT) by about 10% toward 24% at various deposition pressures. The STO gate dielectric with this nitridation treatment exhibited slightly lower leakage current at an accumulation region and nearly 2 orders of magnitude lower leakage current at an inversion region. The repeated spike heating technique was also employed to deposit a STO gate dielectric at repeated oscillating temperatures. The results show that this thermal treatment reduced the interfacial trap states and the leakage current was also reduced by about 1 order of magnitude at the same EOT. (C) 2002 American Institute of Physics.
Electrical properties of metal-ferroelectric-insulator-semiconductor using sol-gel derived SrBi2Ta2O9 film and ultra-thin Si3N4 buffer layer
(2002-12-02)
Huang, CH
;
Tseng, TY
;
Chien, CH
;
Yang, MJ
;
Leu, CC
The electrical properties of the metal-ferroelectric-insulator-silicon memories with stacked gate configuration of Pt/ SrBi2Ta2O9 (SBT)/Si3N4/p-Si (1 0 0) were investigated. In an attempt to operate at low voltage with sufficient large memory window, various ultra-thin Si3N4 buffer layers in thickness of 3.5, 2, and 0.9 nm were employed. From the results of C-V measurements, the memory window can be as large as 0.8 V at the bias amplitude of 5 V for the sample with 0.9 nm SixNy buffer layer. Well-crystallized perovskite structures have been further confirmed by the spectra of X-ray diffraction measurements. The leakage current, which plays a very important role in the data retention, of Pt/SBT (245 nm)/Si3N4 (0.9 nm)/p-Si (10 0) can be as low as 2.5 X 10(-8) A/cm(2) at 200 kV/cm. Excellent fatigue-free performance with up to 10(10) read/write cycles and good retention time of > 2 h have been obtained. Optimization and scaling of SBT thin films are believed to be effective in pursuing extremely low voltage operation, high-density and liable 1T nonvolatile ferroelectric random access memories. (C) 2002 Elsevier Science B.V. All rights reserved.
Growth of the large area horizontally-aligned carbon nanotubes by ECR-CVD
(2002-12-02)
Hsu, CM
;
Lin, CH
;
Chang, HL
;
Kuo, CT
;
材料科學與工程學系
For potential applications of carbon nanotubes (CNTs) as connectors in microelectronic devices, the process to synthesize the large area horizontally-aligned CNTs on 100 mm (4 inch) Si wafers was developed, using electron cyclotron resonance chemical vapor deposition, with CH, and H, as the source gases and Co as the catalyst. The results show that vertical and horizontal CNTs can be obtained by manipulating the electric field applied on the substrate and flow direction of the gases. In the present deposition conditions, the horizontal CNTs show better field emission properties than vertical CNTs. This may be due to the blocking effect of catalysts at the tips and to the diminishment of the effective emission area from defects of vertical CNTs body. (C) 2002 Elsevier Science B.V. All rights reserved.
Growth of carbon nanotubes by microwave plasma chemical vapor deposition using CH4 and CO2
(2002-12-02)
Chen, M
;
Chen, CM
;
Chen, CF
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Carbon nanotubes (CNTs) were grown vertically and aligned on Fe catalytic nanoparticles which were deposited on a Si substrate at low temperature using CH4 and CO2 gas mixtures. A dynamic form of optical emission spectroscopy was used to C detect the species in the plasma. These data show the dominant species in gas phase reaction. The composition of plasma significantly affects the reaction mechanism of CNTs growth and diamond film synthesis. The growth quality of CNTs is better C than a conventional reaction in a gas mixture of hydrogen and hydrocarbons. However, the highest yield of CNTs of approximately 70% was obtained by microwave plasma chemical vapor deposition for CH4-CO2 gas mixture at a flow rate of CH4/CO2 at 96%, power supply of 300 W, reaction time of 20 min and bias voltage of 150 V In summary, the oxygen containing in the CH4-CO2 gas system can increase the amount of C-2 In the C-2-rich plasma the excited C-2 emission at a higher intensity is beneficial to graphite deposition, which enhances CNTs synthesis on catalyst-deposited surface quality. (C) 2002 Elsevier Science B.V. All rights reserved.
Iron and cobalt silicide catalysts-assisted carbon nanostructures on the patterned Si substrates
(2002-12-02)
Chang, HL
;
Lin, CH
;
Kuo, CT
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Catalyst-assisted carbon nanotubes (CNTs) and carbon nano-rods were synthesized on the patterned or un-patterned Si wafer by microwave plasma chemical vapor deposition, using iron or cobalt silicide catalysts. Controllable carbon nanostructures were achieved by manipulating carbon and nitrogen concentration in the source gases, catalyst materials, and patterned wafer application. CNTs were synthesized under a high ratio of CH4/H-2 = 0.1, while carbon nano-rods were synthesized under a low ratio of CH4/H-2=0.01. Introducing N-2 gas into CH4/H-2 source gases gives rise to bamboo-like CNTs formation. Selective CNTs depositions were applied on (a) parallel Fe-coated line arrays, (b) CoSix-coated hole arrays. This is a novel method that is compatible with Si microelectronic device manufacturing. The field emission results indicate that the emission current density can be above 1 mA/cm(2) at 3.97 V/mum, and hollow like CNTs belong to better emission current than bamboo-like CNTs. Growth models of different carbon nanostructures are proposed. (C) 2002 Elsevier Science B.V. All rights reserved.
Crystallization behavior of syndiotactic polystyrene nanocomposites for melt- and cold-crystallizations
(2002-12-05)
Tseng, CR
;
Wu, SC
;
Wu, JJ
;
Chang, FC
;
應用化學系
Analyses of the effects of montmorillonite (clay) on the crystallinity and crystallization behavior of syndiotactic polystyrene (s-PS) were investigated by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The dispersibility of the clay in s-PS nanocomposites was studied by X-ray and transmission electron microscopy (TEM). The clay was dispersed into the s-PS matrix by melt blending on a scale of 1-2 nm or few tenths-100 nm, depending on the surfactant treatment. On adding clay, the crystallization behavior of the s-PS tends to convert into the beta-crystal from the alpha-crystal after being cold-crystallized because the clay plays a vital role in facilitating the formation of the thermodynamically favored beta-form crystal when the s-PS is cold- or melt-crystallized. This phenomenon leads to a change in a conventional mechanism of molecular packing for the s-PS. Evidently, the clay significantly affects the crystallinity and crystallization behavior of the s-PS. (C) 2002 Wiley Periodicals, Inc.
「四小門閥」展覽
(2002-12-06)
本報訊
四小門閥作品展明登場
(2002-12-06)
本報訊
Analysis of chitin oligosaccharides by capillary electrophoresis with laser-induced fluorescence
(2002-12-06)
Wang, CY
;
Hsieh, YZ
;
應用化學系
;
Department of Applied Chemistry
A method, using capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection for analyzing chitin oligosaccharides is described. Chitin oligosaccharides were derivatized with 9-aminopyrene-1,4,6-trisulfonate (APTS) via reductive amination at 37 degreesC for 16 h (optimized conditions). The APTS-chitin oligosaccharides were analyzed using either an acidic citric acid-phosphate buffer or an alkaline borate buffer. The effects of buffer types, buffer pH values, and buffer concentrations on the separation were examined. The analytes were successfully separated by using a pH 4.6 citric acid-phosphate within 19 min. The APTS-derivatized chitin monosaccharide (D-glucosamine) migrated first. The analytes were also completely separated by using a pH 9.0 borate buffer within 24 min. Moreover, the specificity of enzyme digestion on chitin polysaccharides using the optimized APTS labeling procedure and the CE-LIF method was demonstrated. (C) 2002 Elsevier Science B.V. All rights reserved.
月亮小手外一章
(2002-12-07)
管管
管管等人舉辦 <四人門閥>聯展
(2002-12-07)
本報訊
Elastic solutions for stresses in a transversely isotropic half-space subjected to three-dimensional buried parabolic rectangular loads
(2002-12-10)
Wang, CD
;
Liao, JJ
;
土木工程學系
;
Department of Civil Engineering
In many areas of engineering practice, applied loads are not uniformly distributed but often concentrated towards the centre of a foundation. Thus, loads are more realistically depicted as distributed as linearly varying or as parabola of revolution. Solutions for stresses in a transversely isotropic half-space caused by concave and convex parabolic loads that act on a rectangle have not been derived. This work proposes analytical solutions for stresses in a transversely isotropic half-space, induced by three-dimensional, buried, linearly varying/uniform/parabolic rectangular loads. Load types include an upwardly and a downwardly linearly varying load, a uniform load, a concave and a convex parabolic load, all distributed over a rectangular area. These solutions are obtained by integrating the point load solutions in a Cartesian coordinate system for a transversely isotropic half-space. The buried depth, the dimensions of the loaded area, the type and degree of material anisotropy and the loading type for transversely isotropic half-spaces influence the proposed solutions. An illustrative example is presented to elucidate the effect of the dimensions of the loaded area, the type and degree of rock anisotropy, and the type of loading on the vertical stress in the isotropic/transversely isotropic rocks subjected to a linearly varying/uniform/parabolic rectangular load. Copyright (C) 2002 John Wiley Sons, Ltd.
Numerical range of Aluthge transform of operator
(2002-12-15)
Wu, PY
;
應用數學系
;
Department of Applied Mathematics
For any operator A on a Hilbert space, let (A) over tilde denote its Aluthge transform. In this paper, we prove that the closure of the numerical range of (A) over tilde is always contained in that of A. This supplements the recently proved case for dim ker A less than or equal to dim ker A* by Yamazaki, and partially confirms a conjecture of Jung, Ko and Pearcy. (C) 2002 Elsevier Science Inc. All rights reserved.
尖石黑色部落植入文學步道
(2002-12-15)
李令儀
New nanometer T-gate fabricated by thermally reflowed resist technique
(2002-12-15)
Lee, HM
;
Chang, EY
;
Chen, SH
;
Chang, CY
;
電子工程學系及電子研究所
Novel nanometer T-gate process has been developed utilizing electron beam (EB) lithography and thermally reflowed resist technique. Through well-controlled EB exposure dosage, heating time and reflow temperature; the resist structures can be efficiently reflowed to form the desired T-gate configuration with dimension ranging from 150 nm to 30 nm. After Ti/Pt/Au metal deposition by electron gun evaporation and lift-off process, the nanometer T-gates with thickness of about 500 nm were formed. With the optimized conditions, ultra-short 30 nm T-shaped gate was clearly demonstrated on the GaAs substrate. This is the smallest T-gate reported with the thermally reflowed technique in the literature so far and can practically be used in the GaAs monolithic microwave integrated circuit (MMIC) fabrications.
Fabrication of light-shaping diffusion screens
(2002-12-15)
Lu, YT
;
Chi, S
;
光電工程學系
;
Department of Photonics
This study presents the fabrication of alight-shaping diffuser, made by recording the far field laser speckles projected from a ground glass on photoresist plate. Elliptical speckles are created by illuminating the ground glass with a line shape He-Cd laser beam. The recorded elliptical speckles can diffuse incident light into different spread angles in vertical and horizontal directions. The speckles are inscribed with the appropriate density and depth on the surface, to diffuse incident light uniformly without a hot spot, by controlling the separation and duration of exposures. A nickel master is then electro-formed from the speckled plate for embossing the pattern on plastic plate for mass production. The diffuser is used in front and rear projection screens with high gain, the displays of ATMs, LED display illumination shapers, LCD backlight and laser beam shaping homogenizers as well as other applications. (C) 2002 Elsevier Science B.V. All rights reserved.
Generalization of Yang et al.'s method for fuzzy programming with piecewise linear membership functions
(2002-12-16)
Lin, CC
;
Chen, AP
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Li and Yu (Fuzzy Sets and Systems 101 (1999) 109) argued that the model of Yang et al. for fuzzy programming (Fuzzy Sets and Systems 41 (1991) 39) is correct only for a specific type of piecewise linear membership function and proposed their model for other type of membership functions. This study generalizes the model of Yang et al. A numerical example indicates that the model of Li and Yu is inapplicable to a fuzzy programming problem that involves more than one membership function, whereas the proposed model gives the optimal solution. (C) 2002 Elsevier Science B.V. All rights reserved.
Ring embedding in faulty honeycomb rectangular torus
(2002-12-16)
Cho, HJ
;
Hsu, LY
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
Assume that m and n are positive even integers with n greater than or equal to 4. The honeycomb rectangular torus HReT(m,n) is recognized as another attractive alternative to existing torus interconnection networks in parallel and distributed applications. It is known that any HReT(m, n) is a 3-regular bipartite graph. We prove that any HReT(m, n) - e is hamiltonian for any edge e is an element of E(HReT(m, n)). Moreover, any HReT(m, n) - F is hamiltonian for any F = {a, b} with a is an element of A and b is an element of B where A and B are the bipartition of HReT(m, n), if n greater than or equal to 6 or m = 2. (C) 2002 Elsevier Science B.V. All rights reserved.
Polycrystalline silicon thin-film transistor with self-aligned SiGe raised source/drain
(2002-12-16)
Peng, DZ
;
Chang, TC
;
Shih, PS
;
Zan, HW
;
Huang, TY
We have fabricated a polycrystalline silicon thin-film transistor with self-aligned SiGe raised source/drain (SiGe-RSD TFT). The SiGe-RSD regions were grown selectively by ultrahigh vacuum chemical vapor deposition at 550 degreesC. It was observed that, with SiH4 and GeH4 gas flow rates of 5 and 2 sccm, respectively, the poly-SiGe could be selectively grown up to 100 nm for source/drain regions. The resultant transistor structure features an ultrathin active channel region (20 nm) and a self-aligned thick source/drain region (120 nm), which is ideally suited for optimum performance. The significant improvements in electrical characteristics, such as higher turn-on current, lower leakage current, and higher drain breakdown voltage have been observed in the SiGe-RSD TFT, compared to the conventional TFT counterpart. These results indicate that TFTs with SiGe raised source/drain structure would be highly promising for ultrathin TFTs applications. (C) 2002 American Institute of Physics.