Browsing by Author "Chen, JK"

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Behavior and surface energies of polybenzoxazines formed by polymerization with argon, oxygen, and hydrogen plasmas
(2004-11-15)
Chen, JK
;
Lin, IK
;
Ko, FH
;
Huang, CF
;
Chen, KS
Polybenzoxazine (PBZZ) thin films can be fabricated by the plasma-polymerization technique with, as the energy source, plasmas of argon oxygen or hydrogen atoms and ions. When benzoxazine (BZZ) films are polymerized through the use of high-energy argon atoms, electronegative oxygen atoms, or excited hydrogen atoms, the PBZZ films that form possess different properties aid morphologies in their surfaces. High-energy argon atoms provide a thermodynamic factor to initiate the ring-opening polymerization of BZZ and result in the polymer surface having a grid-like structure. The ring-opening polymerization of the BZZ film that is initiated by cationic species such as oxygen atoms in plasma, is propagated around nodule structures to form the PBZZ. The excited hydrogen atom plasma initiates both polymerization and decomposition reactions simultaneously in the BZZ film and Results in the formation of a porous structure on the PBZZ surface. We evaluated the surface energies of the PBZZ films polymerized by the action of these three plasmas by measuring the contact angles of diiodomethane and water droplets. The surface roughness of the films range from 0.5 to 26 nm, depending on the type of carrier gas and the plasma-polymerization time. By estimating changes in thickness, we found that tie PBZZ film synthesized by the oxygen plasma-polymerization process undergoes the slowest rate of etching in CF(4) plasma. (C) 2004 Wiley Periodicals, Inc.
Comparison of oxide breakdown progression in ultra-thin oxide SOI and bulk pMOSFETs
(2004)
Chan, CT
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Kuo, CH
;
Tang, CJ
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Chen, MC
;
Wang, TH
Accelerated oxide breakdown progression in ultra-thin oxide (1.4nm) SOI pMOSFETs is observed, as compared to bulk devices. The accelerated progression is explained by the increase of hole stress current as a result of breakdown induced channel carrier heating in a floating-body configuration. Numerical simulation of hole tunneling current and hot carrier luminescence measurement are carried out to justify the proposed theory.
Double graded-gap hydrogenated amorphous silicon carbide thin-film light-emitting diode with composition-graded N layer and carbon-increasing P layer
(1996-02-01)
Chen, YA
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Chen, JK
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Tsay, WC
;
Laih, LH
;
Hong, JW
An hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diode (TFLED), in which a composition-graded n layer and carbon-increasing p layer respectively replace the constant optical-gap p-a-SiC:H layer and n-a-SiC:H layer employed in the previously reported double graded-gap (DG) TFLED and which contains dopant-graded p-i and i-n junctions, was successfully fabricated tu improve the electroluminescence (EL) of TFLED. This device had a brightness of 400 cd/m(2) at an injection current density of 600 mA/cm(2) and its EL threshold voltage (V-th) was only 9.0 V. The device EL spectrum showed a peak at 586 nm wavelength and emitted yellowish-orange light. The proposed TFLED had good stability of EL intensity and the EL spectrum during normal operation. The optimum conditions of rapid thermal annealing (RTA), which improved the ohmic contact between the amorphous layer and external electrode of the device, were 5 min at 300 degrees C in a 250 Torr H-2 ambient.
Effect of fluoroalkyl substituents on the reactions of alkylchlorosilanes with mold surfaces for nanoimprint lithography
(2004-11-01)
Chen, JK
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Ko, FH
;
Hsieh, KF
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Chou, CT
;
Chang, FC
We have applied trichloro(3,3,3-trifluoropropyl)silane (FPTS) and trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane (FOTS) for the preparation of self-assembled film on a silicon mold for use as releasing, antisticking layers for nanoimprint lithography. From contact angle measurements. we have determined the surface energies of the molds in terms of their Lewis acid, Lewis base, and van der Waals components. The surface energies of the FPTS- and FOTS-derived film decreased as the annealing temperature and immersion time increased. Suitable self-assembled films were prepared by annealing at 150 degreesC for at least 1 h. The surface roughnesses of the self-assembled film formed from FPTS and FOTS were 0.468 and 0.189 nm. respectively. The lower surface energy and roughness of the FOTS-derived film on the silicon mold prevent both the adhesion and defect-formation problems from occurring during resist imprinting. The self-assembled films prepared on the mold are resistant to immersion in acid and base, but treatment with oxygen plasma has an adverse effect on these molds' stabilities. (C) 2004 American Vacuum Society.
Fabricating and characterizing oblique polymer structures by electron beam writing on resist-coated SiO2 wafers
(2006-04-01)
Ko, FH
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Chen, JK
;
Chang, FC
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材料科學與工程學系奈米科技碩博班
;
應用化學系
We have successfully fabricated SU-8 materials having oblique structures by a new electron beam technology.-We studied the contrast, sensitivity, etching, and thermal properties of SU-8, PMMA, and KrF resists to evaluate their suitability for the fabrication of oblique structures. Among these resists, SU-8 revealed the lowest contrast ratio, highest throughput, and best thermal stability, and so it became the candidate material for patterning the oblique structures. The technique we have developed involves five regional exposures of a thick SU-8 resist layer with various electron beam dosages. Furthermore, we discuss the surface morphology, reaction mechanism, and hydrophobicity after subjecting the SU-8 resist to a series of plasma treatments. The formation of surface nano-nodules during oxygen plasma treatment explains the surface hydrophobicity. We have carefully evaluated the effects of the electron beam writing dose and the design of the exposure area with respect to the inclined angle of the fabricated structure. (c) 2006 Elsevier B.V. All rights reserved.
In situ characterization of CuCMP slurry and defect reduction using IR thermal camera
(2004-09-01)
Chan, CH
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Chen, JK
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Chang, FC
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應用化學系
;
Department of Applied Chemistry
In order to choose appropriate property of Cu chemical-mechanical polishing (CMP) slurry, we used IR thermal camera to distinguish this slurry that belonged to Preston or non-Preston. The adoption of the IR thermal camera is to choose suitable non-Preston Cu CMP slurry in situ and find out optimal changing timing of step endpoint. Additionally supplementing robust CMP machine, appropriate Cu film quality and pre-treatment, we could obtain a total defect number is less than 10(1) order and achieve excellent Cu CMP performance. Such Cu CMP technology resulting in Cu damascene process work and make sure 0.13 mum and beyond 100 nm Cu process to be reliable and practical. (C) 2004 Published by Elsevier B.V.
Low RF loss and noise of transmission lines on Si substrates using an improved ion implantation process
(2003)
Chan, KT
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Chin, A
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McAlister, SP
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Chang, CY
;
Tseng, C
Very low power loss less than or equal to 0.6 dB at 110 GHz and noise of < 0.25 dB at 18 GHz have been measured on transmission lines fabricated on Si substrates and implanted with proton. In contrast, much worse power loss of 5 dB and higher noise of 2.5 dB were measured without implantation. This large improvement arises from the high resistivity by proton implantation, which was also done after forming the transmission lines and at a reduced energy of similar to 4 MeV for easier process integration into current VLSI technology.
Mechanism and modeling of ring pattern formation for electron beam exposure on Zwitterresist
(2003-06-01)
Chen, JK
;
Ko, FH
;
Chen, HL
;
Chang, FC
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應用化學系
The novel sensitivity curve was determined for the zwitterresist. The irradiation dose in the center could create a ring pattern due to simultaneous exhibition of the positive tone and negative tone of zwitterresist. The natural logarithm dependence of ring width and electron beam dose was linear in two ranges, irrespective of the dot design radius. The heating effect was identified from 600 muC/cm(2), while it could be neglected at less than 600 muC/cm(2). Mathematical modeling for the prediction of ring width for zwitterresist, was achieved by considering the electron scattering and heating effects. The results of experimental measurement and modeling on ring width showed a very good correlation.
Negative substrate bias enhanced breakdown hardness in ultra-thin oxide pMOSFETs
(2003)
Wang, TH
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Tsai, CW
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Chen, MC
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Chan, CT
;
Chiang, HK
Negative substrate bias enhanced breakdown hardness in ultra-thin oxide (1.4nm) pMOS is observed. This result is believed due to the increase of hole stress current during breakdown progression via breakdown induced carrier heating. Numerical analysis of substrate bias effect on hole tunneling current is performed to support the proposed theory. This phenomenon is particularly significant to gate oxide reliability in floating substrate (PD-SOI) or forward-biased substrate devices.
RF passive devices on Si with excellent performance close to ideal devices designed by electro-magnetic simulation
(2003)
Chin, A
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Chan, KT
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Huang, CH
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Chen, C
;
Liang, V
High quality RF inductors, very low loss and noise CPW and microstrip lines, advanced broad and narrow band filters, and ring resonators have been achieved on Si substrates, using an optimized proton implantation process. The RF performance up to 100 GHz is close to that for ideal devices designed by EM simulation for lossless substrates.
Structural transformation of acrylic resin upon controlled electron-beam exposure yields positive and negative resists
(2005-07-01)
Chen, JK
;
Ko, FH
;
Chang, TC
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材料科學與工程學系奈米科技碩博班
;
應用化學系
Zwitter polymers are defined as polymers that undergo transformation from a linear to a crosslinked structure under electron-beam irradiation. A resist polymer may be either linear or crosslinked, depending on electron-beam dosage. The structural transformation of acrylic resin make it suitable for applications in positive and negative resists in the semiconductor field. The contrast ratio and threshold dose both increase with increasing resist thickness for both the positive and negative resists, while the positive resist exhibits better contrast than the negative. The intensity of the characteristic Fourier-transform infrared absorption band at 161.2 cm(-1) (vinyl group) is used to explain the phenomena behind these resist transformations. We evaluate the effects of two important processing conditions: the soft baking and post-exposure baking temperatures. Pattern resolution decreases upon increasing the baking temperature, except for soft baking of the negative resist. The effect of electron dose on the pattern resolution is also discussed in detail for both resists. High electron-beam exposure does not improve the etching resistance of the resist because of the porous nature of the resist that develops after high-dosage irradiation.
Syntheses, thermal properties, and phase morphologies of novel benzoxazines functionalized with polyhedral oligomeric silsesquioxane (POSS) nanocomposites
(2004-08-19)
Lee, YJ
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Kuo, SW
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Su, YC
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Chen, JK
;
Tu, CW
We have successfully synthesized a novel benzoxazine ring-containing polyhedral oligomeric silsesquioxane (BZ-POSS) monomer by two routes: (1) hydrosilylation of a vinyl-terminated benzoxazine using the hydro-silane functional group of a polyhedral oligomeric silsesquioxane (H-POSS) and (2) reaction of a primary amine-containng POSS (Amine-POSS) with phenol and formaldehyde. The benzoxazine-containing POSS (BZ-POSS) monomer can be copolymerized with other benzoxazine monomers through ring-opening polymerization under conditions similar to that used for polymerizing pure benzoxazines. Thermal properties of these POSS-containing organic/inorganic polybenzoxazine nanocomposites have been improved over the pure polybenzoxazine analyzed by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The BZ-POSS monomer is poorly miscible with the benzoxazine monomer and tends to aggregate and forms its own domains, both before and after polymerization. At a higher BZ-POSS content, gross aggregation occurs and results in a lower than expected improvement in the thermal properties. (C) 2004 Elsevier Ltd. All rights reserved.
Synthesis and characterization of polystyrene-b-poly(4-vinyl pyridine) block copolymers by atom transfer radical polymerization
(2005-12-01)
Huang, CF
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Kuo, SW
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Chen, JK
;
Chang, FC
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應用化學系
We aimed at the synthesis of well-define PS-b-P4VP by using atom transfer radical polymerization in two-step process. First, polystyrenes with benzyl bromide end group (PS-Br; by ATRP) were prepared as macroinitiator for the next ATRP of 4-vinyl pyridine and characterized these polymers from H-1-NMR and MALDI-TOF. Comparing with MALDI-TOF-MS, H-1-NMR and GPC analyses, this indicates that the formation of the block copolymer can be observed. During the polymerizations, molecular weight distribution and kinetics have been evaluated from GPC traces and H-1-NMR analyses. We further characterized the thermal properties of these block polymers by DSC and TGA. DSC measurement on the PS-b-P4VP block copolymers exhibited two glass transitions, indicating that the resulting block copolymers are phase separated. Two maxima differential peaks were observed on the TGA trace for the PS-b-P4VP block copolymers might be assigned to the decomposition of the P4VP blocks at 380 degrees C and the PS blocks at higher temperature.
Synthesis and characterizations of a vinyl-terminated benzoxazine monomer and its blending with polyhedral oligomeric silsesquioxane (POSS)
(2005-03-10)
Lee, YJ
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Huang, JM
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Kuo, SW
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Chen, JK
;
Chang, FC
Benzoxazine was synthesized through the Mannich condensation of phenol, formaldehyde, and primary amines through ring-opening polymerization. Polybenzoxazines are phenolic-like materials that possess dimensional and thermal stability, and they release no toxic byproducts during their polymerization. To further improve the thermal stability of polybenzoxazines, a hydrosilane-functionalized polyhedral oligomeric silsesquioxane (H-POSS) was incorporated into the vinyl-terminated benzoxazine monomer (VB-a) which we then subjected to ring-opening polymerization. In addition, we also prepared hybrids from a non-reactive POSS (IB-POSS) and VB-a. The glass transition temperature (T-g) of a regular polymerized VB-a (i.e. PVB-a) is 307 degrees C, while the hybrid containing 5 wt% of H-POSS is 333 degrees C. The IB-POSS modified PVB-a hybrids, in general, results in lower T-g than the pure PVB-a due to poor missibility. (c) 2005 Elsevier Ltd. All rights reserved.
The minimum noise figure and mechanism as scaling RF MOSFETs from 0.18 to 0.13 mu m technology nodes
(2003)
Huang, CH
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Chan, KT
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Chen, CY
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Chin, A
;
Huang, GW
As scaling down the RF MOSFET from 0.18 to 0.13 mum technology nodes, the f(T) increases but the NFmin becomes worse by increasing similar to0.2 dB. A small NFmin of 0.93 dB is measured at 5.8 GHz in 0.18 mum MOSFET using 50 fingers but increases as either increasing or decreasing finger number. This abnormal dependence and higher noise at 0.13 mum is accurately analyzed by equivalent circuit model and due to the combined gate resistance and substrate effect.
Thermal properties, miscibility and specific interactions in comparison of linear and star poly(methyl methacrylate) blend with phenolic
(2004-08-05)
Huang, CF
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Kuo, SW
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Lin, HC
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Chen, JK
;
Chen, YK
A series of miscible linear and star poly(methyl methacrylate) (PMMA)/phenolic blends with different compositions have been prepared. T(g)s of both systems are negative derivation from the average values, implying that the self-association interaction is stronger than the inter-association interaction between linear or star PMMA with phenolic. The proton spin-lattice relaxation time in the rotating frame (T-1rho(H)) determined by high resolution solid state C-13 NMR indicates single composition dependent T-1rho(H) from all blends, implying a good miscibility with chain dynamics on a scale of 1-2 nm. However, T(1rho)(H)s of star PMMA/phenolic blends are relatively smaller than those of linear PMMA/phenolic blends, implying that the degree of homogeneity of star PMMA/phenolic blends is higher than those of linear PMMA/phenolic blends. According to FT-IR analyses, the above results can be rationalized that the hydrogen-bonding interaction of the star PMMA/phenolic blends is greater than the corresponding linear PMMA/phenolic blends. (C) 2004 Elsevier Ltd. All rights reserved.
Thermal properties, specific interactions, and surface energies of PMMA terpolymers having high glass transition temperatures and low moisture absorptions
(2005-03-10)
Chen, JK
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Kuo, SW
;
Kao, HC
;
Chang, FC
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應用化學系
We have prepared a series of poly(methyl methacrylate) (PMMA)-based terpolymers that have high glass transition temperatures and low moisture absorptions by the free radical copolymerization of methyl methacrylate, methacrylamide, and styrene in dioxane. We have investigated the effects of the styrene content on the glass transition temperatures, hydrogen bonding interactions, surface energies, moisture absorption, and molecular weights of these poly(methyl methacrylate-co-methacryl ami de-co-styrene) (Poly(MMA-co-MAAM-co-S)) terpolymers by differential scanning calorimetry, Fourier transform infrared and X-ray photoelectron spectroscopies, contact angle measurements, and gel permeation chromatography. The results indicate that the glass transition temperatures, hydrogen bonding strengths, surface energies, molecular weights, and the moisture absorption decreased upon increasing the PS content in most of the terpolymer systems. In addition, the moisture absorptions of some selected terpolymers decreased even through they possess higher values of T, than pure PMMA. These selected terpolymers have the potential to replace pure PMMA in optical device applications. (c) 2005 Elsevier Ltd. All rights reserved.