Browsing by Author "Lin, Ho-May"

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Characterization of negative-type photoresists containing polyhedral oligomeric silsesquioxane methacrylate
(2008-07-01)
Lin, Ho-May
;
Hseih, Kuo-Hung
;
Chang, Feng-Chih
;
應用化學系
;
Department of Applied Chemistry
A series of negative-type photoresists made by blending with various contents of polyhedral oligomeric silsesquioxane (POSS) methacrylate were prepared and characterized. These POSS macromers tend to crystallize or aggregate to form their own domains within the photoresist matrix. Sensitivity of the POSS modified photoresist is significantly improved with the increase of the POSS content. Results from photo-DSC analyses indicate that both induction time and peak maximum of heat flux are reduced by blending with POSS macromer. Addition of the proper amount (<13 wt%) of POSS can effectively increase photo-polymerization rate and exothermic heat. Hydrogen bonding interaction between the hydroxyl of photoresist and the siloxane of POSS tends to attract methacrylate double bonds surrounding POSS particles locally and thus enhances the rate of photo-polymerization and sensitivity. (C) 2008 Elsevier B.V. All rights reserved.
Photo-polymerization of photocurable resins containing polyhedral oligomeric silsesquioxane methacrylate
(2011-12-15)
Lin, Ho-May
;
Wu, Shi-Yin
;
Chang, Feng-Chih
;
Yen, Ying-Chieh
;
應用化學系
Photocurable resins, bisphenol A propoxylate glycerolate diacrylate (BPA-PGDA, containing two hydroxyl) and bisphenol A propoxylate diacrylate (BPA-PDA), with fixed photoinitiator (Irgacure 907) concentration and various contents of methacrylisobutyl polyhedral oligomeric silsesquioxane (MI-POSS) were prepared and characterized by FTIR spectroscopy, scanning electron microscope and differential photocalorimetry. The MI-POSS molecules form crystals or aggregated particles in the cured resin matrix. The BPA-PGDA series photocurable resins show higher viscosity and lower photo-polymerization reactivity than the BPA-PDA series resins. The photo-polymerization rate and conversion of BPA-PGDA series are improved with increasing MI-POSS content. On the contrary, the photo-polymerization behavior of BPA-PDA series photocurable resins remains nearly unchanged by the addition of MI-POSS. Hydrogen-bonding interaction between the hydroxyl of BPA-PGDA and the siloxane of MI-POSS tends to attract and concentrate these acrylate double bonds around MI-POSS particles and thus enhances the photo-polymerization rate and conversion. (C) 2011 Elsevier B.V. All rights reserved.
Polyhedral oligomeric silsesquioxane containing copolymers for negative-type photoresists
(2006-09-22)
Lin, Ho-May
;
Wu, Shi-Yin
;
Huang, Pei-Yuan
;
Huang, Chih-Feng
;
Kuo, Shiao-Wei
A series of methacrylate copolymers containing polyhedral oligomeric silsesquioxane (POSS) was synthesized from the free radical copolymerization of methacrylic acid, methyl methacrylate, and isobutyl propylmethacryl polyhedral oligosilsesquioxanes, and then were modified with glycidyl methacrylate to serve as negative-type photoresists. The UV/Vis spectroscopy reveals that the incorporation of POSS moiety into the copolymer results in a slight decrease in transparency from 99 to 92.5% (at wavelength = 365 nm). The photosensitivity in terms of resist sensitivity (D-n(0.5)), contrast (gamma), and photopolymerization rate are significantly increased with increase in the POSS content. In addition, the induction time is reduced from 0.520 to 0.515 min after incorporating the POSS unit based on photo-DSC analyses. These observed results can be rationalized as due to hydrogen bonding interactions between siloxane and hydroxyl groups in copolymers which tend to attract the methacrylate double bonds surrounding POSS units to crosslink, thereby enhancing the photopolymerization rate and sensitivity. We further evaluate the lithographic property of a photoresist under a collimated exposure.
Supramolecular aggregations through the inclusion complexation of cyclodextrins and polymers with bulky end groups
(2007-01-01)
Chan, Shih-Chi
;
Kuo, Shiao-Wei
;
She, Hwo-Shuenn
;
Lin, Ho-May
;
Lee, Hsin-Fang
Mono-polyhedral oligomeric sillsesquioxane-end capped poly(epsilon-caprolactone) (mPPCL) can form inclusion complexes (ICs) with alpha- and gamma-cyclodextrins (CDs) but not with beta-CD. These CD ICs have been characterized with X-ray diffraction, solid-state C-13 cross-polarization/magic-angle-spinning NMR spectroscopy, H-1 NMR spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and scanning electron microscopy. The poly(epsilon-caprolactone) (PCL) chain of mPPCL is included within the channel provided by the CDs to form a columnar, crystalline structure. The PCL/CD ratios determined by H-1 NMR spectroscopy for the ICs with alpha- or gamma-CDs are higher than the stoichiometries because of the steric hindrance of the bulky polyhedral oligomeric silsesquioxane chain end and result in a fraction of the e-caprolactone units free from complexation with the CDs. On the basis of these analyses, we propose some possible structures for these CD/mPPCL ICs. (c) 2006 Wiley Periodicals, Inc.
Syntheses and specific interactions of poly(epsilon-caprolactone)-block-poly(vinyl phenol) copolymers obtained via a combination of ring-opening and atom-transfer radical polymerizations
(2006-11-01)
Kuo, Shiao-Wei
;
Huang, Chih-Feng
;
Lu, Chu-Hua
;
Lin, Ho-May
;
Jeong, Kwang-Un
A series of PCL-b-PVPh diblock copolymers were prepared through combinations of ring-opening and atom-transfer radical polymerizations of c-caprolactone and 4-acetoxystyrene, and subsequent selective hydrolysis of the acetyl protective group. This PCL-b-PVPh diblock copolymer shows a single glass transition temperature over the entire composition range, indicating that this copolymer is able to form a miscible amorphous phase due to the formation of intermolecular hydrogen bonding between the hydroxyl of PVPh and the carbonyl of PCL. In addition, DSC analyses also indicated that the PCL-b-PVPh diblock copolymers have higher glass transition temperatures than their corresponding PCL/PVPh blends. FT-IR was used to study the hydrogen-bonding interaction between the PVPh hydroxyl group and the PCL carbonyl group at various compositions.