A hyperbranched poly(amic acid methyl ester) precursor was prepared from self-polycondensation of an AB₂ type monomer (1) in the presence of (2, 3-dihydro-2-thioxo-3-benzoxazolyl)phosphonic acid diphenyl ester (DBOP) as a condensing agent. End-capping reactions of free amine end groups of the precursor with acetyl, n-heptanoyl chloride, 4-methylphthalic anhydride and 3, 5-bis(4- nitrophenoxy)diphenyl ether-3′, 4′-dicarboxylic anhydride (10) were carried out. By chemical imidization of these precursors in the presence of acetic anhydride and pyridine, hyperbranched aromatic polyimides, which were soluble in NMP, DMF, DMSO and THF, were successfully prepared. By gel permeation chromatography (GPC) measurement, weight-average molecular weights (M_W) of hyperbranched aromatic polyimides were found to be 50000-98000. From IR and ¹H-NMR analyses, it was found that both end-capping and subsequent chemical imidization reactions proceeded quantitatively. The degree of branching (DB) of hyperbranched aromatic polyimides was 0.49 for 4, and 1.0 for 9. By thermogravimetric (TG) and differential scanning calorimetry (DSC) measurements of the hyperbranched aromatic polyimides, 5wt% thermal loss temperatures (T₅) were observed to be above 370°C, and T_g values were 189, 138, 186 and 174°C for polyimides 4, 5, 7 and 9, respectively. The densities of the transparent films of the hyperbranched polyimides having acetoamide end-groups were found to be less than 1.35, which were lower than those of their linear analogues. The film, prepared from the hyperbranched polyimide with 4-methylphthalimide end-groups (7), had lower dielectric constant, birefringence, and shorter cut-off wavelength than the film of poly(4, 4′-oxydiphenylene pyromellitimide).

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A negative-working photosensitive polyimide (PI) precursor based on a low dielectric polyimide precursor having a low coefficient of thermal expansion (CTE) and 1, 4-dihydropyridine (DHP) as a photosensitive compound has been developed. Co-polyamic acid(Co-PAA)s were prepared by ring-opening polyaddition of aromatic dianhydrides with diamines. The dissolution behavior of Co-PAAs containing DHP after exposure was studied and it was found that the difference of dissolution rate between the exposed and unexposed parts was enough to get a high contrast due to the photochemical reaction of DHP in the polymer film. The cured Co- PI film at 380°C showed the low coefficient of thermal expansion of 20ppm and the low dielectric constant of 2.7 at 1MHz.

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Liquid Crystal Display(LCD) is a high performance tool for displaying many kinds of information. Application of LCD is diversifying to notebook PC, monitor display, TV and reflective type of PDA and personal handy phone. To achieve these performance for several applications of LCD, development of new materials has been investigated. Color photoresist is used for color filter production. Negative and positive type of transparent photoresist are applied for leveling and overcoating layer of LCD process, and further used for spacer materials. For the next generation of alignment layer, photo-alignment material is also investigated. Dimerization of chalcone moiety showed good alignment characteristics for liquid crystals and good LCD performance.

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Applications fo polyimides in microelectronics were reviewed. Only materials that can retain sufficient reliability for severe heat conditions(180-400°C) can be used as insulation materials for electronics. Polyimides are an invaluable organic materials that satisfy the heat resistance requirement. For polyimides, fine patterning technologies of below 1 micron have been established. These technologies are sufficient for wiring board applications and passable for LSI wiring. Dielectrics with low k become necessary for high performance electronic products Table 1 lists k for various inorganic materials and organic polymers. Except for Teflon and polyethylene, polyimides give the lowest k. A large number of monomers with a variety of structures offer wide possibilities for molecular design of polyimides. Now-a-days, corresponding to strong demands for better electrical consumer products, many kinds of applications are spreading widely; e.g. LSI buffer coat films, TAB tapes, adhesives for LSI packaging, liquid crystal orientation films, and optical application fields such as waveguides. Polyimides will be more important material in electronics, because of their superior properties coupled with wide design tolerance.

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A positive working photosensitive polyimide based on hyperbranched poly (ether imide) (H-PEI) and 2, 3, 4-tris[1-oxo-2-diazonaphthoquinone-5-sulfonyloxy] benzophenone (D5SB) as a photoreactive compound has been developed. H-PEI was prepared by polycondensation of 3, 5-di-tert-butyldimethylsilyloxyphenyl-4-fluorophthalimide, followed by deprotection of tert-butyldimethylsilyl group with KF-HBr. The H-PEI has an excellent transparency to UV light. The photosensitive polyimide containing 30wt% of D5SB showed a sensitivity of 120MJ•cm^-2 and a contrast of 2.8 when it was exposed to 365nm light followed by developing with a 2.38% aqueous tetramethylammonium hydroxide (TMAH) solution at room temperature.

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Poly(o-hydroxyamide) (3) as a poly(benzoxazole) precursor was prepared by the polycondensation of 2, 2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (1) and N, N′-isophtaloylbis(benzoxazoline-2-thione) (2) in N-methylpyrrolidinone. The resist from the polymerization solution was formulated with diazonaphtoquinone without isolation of 3. A clear positive pattern with 8μm line and space could be obtained when the film was exposed to g-line (436nm), followed by developing with a 0.8wt% aqueous tetramethylammoniumhydroxide (TMAH) solution. The sensitivity and contrast were determined g-line as 80mJ/cm² and 2.2 respectively. The positive image was successfully converted to poly(benzoxazole) pattern by thermal treatment.

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Photosensitive polyimide has enormous potential as a future dielectric interlayer material for potential use in large scale integrated (LSI) circuits. The block copolyimide known as 21-169 was synthesised via a single step polycondensation reaction. This procedure involved reacting dianhydrides with diamines in the presence of γ- valerolactone/pyridine catalyst in a NMP/toluene solvent system at 180°C. This experimentation involves two types of diazonaphtoquinone (DNQ) compound referred to as PC-5 and NT-200. The exposed films were subjected to a developing process using several alkaline aqueous solutions and tetramethylammonium hydroxide (TMAH). A solution of silane coupling reagent was found to be necessary for good adhesion between the polyimide layer and the silicon wafer. In this paper, the resulting products solubility characteristic and pattern shape of the exposed and unexposed areas at 365nm wavelength of light and 700mJ/cm² were investigated. The contrast γ value between the fully exposed and unexposed area was found to be above 1.1. The PC-5 photosensitive material was found to be an effective dissolution inhibitor for polyimide 21-169 in alkaline developer solution (A0).

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A series of poly(urethane-imide) films were prepared by a reaction between poly(amide acid) and polyurethane prepolymer. Poly(amide acid) was prepared from pyromellitic dianhydride and 4, 4′-oxydianiline. Polyurethane prepolymer was prepared by a reaction of polyether polyol with tolylene-2, 4-diisocyanate and then with phenol as an endcap. The blend films obtained by casting and then drying were transparent. The films still remained transparent after heat treatment at 200°C. The films had characteristics of either elastomer or plastic depending on the polyurethane content. The elongation of the elastomer was as large as ca. 500-1000%. From viscoelastic analyses of the poly(urethane-imide) films, polyimide and polyurethane components were found to be phase separated in the film. By thermally decomposing only the thermally labile polyurethane domains at 300-400°C, polyimide films were obtained. The scanning electron microscopy of the polyimide films suggested the formation of pore of ca. 50nm size.

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A comparison between argon (Ar) and water vapor that were added to plasma copolymerization of trifluoromethanesulfonic acid (TFMS) with octafluorocyclobutane (OFCB) was studied by means of measurement of a deposition rate of the polymer, X-ray photoelectron spectroscopy, and emission spectrochemical analysis. All data obtained from the three measurements suggested that splitting of F atom from OFCB by Ar formed a bonding site, where C-C bond was formed and sulfonic acid functional group (-SO₃H) derived from TFMS was taken up more efficiently. In respect of water vapor, a suppression effect on dissociation of F atom from TFMS and production of HF together with some active species containing O, e.g., O₃, were indicated. These species should contribute to suppression of rapid ablation by F radicals and preservation of -SO₃H.

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The film of expanded polytetrafluoroethylene (ePTFE) grafted with acrylic acid (ePTFE-g-PAA) was prepared by the combined use of oxygen plasma treatment and photografting technique changing plasma-treated time, monomer concentration and UV irradiation time. The permeation of insulin through the ePTFE-g-PAA film can be controlled by the pH change in the medium. Since GOD immobilized onto ePTFE-g-PAA film through covalent bonding can enzymatically react with glucose, we have tried to control the permeation of insulin through the GOD immobilized ePTFE-g-PAA film due to pH lowering in medium.

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In this work we characterize pulsed inductively coupled of plasmas of two organic precursor molecules, isopropyl alcohol and 1, 4 dioxane using Langmuir probes and in-situ mass spectrometry. We identify the key ionized species diffusing to the substrate and offer an explanation as to how they are generated. We also analyze the deposited films using X-ray Photoelectron Spectroscopy and suggest a correlation between the measured plasma ion mass distributions and chemical bonding character of the deposit. The ultimate goal of this work is to develop predictable models for PECVD processes for thin polymer films with functionalized surfaces.

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Pyrrole, thiophene, and furan were plasma polymerized on low-density polyethylene (LDPE) film. The deposition rate of pyrrole and thiophene was relatively high and similar at various conditions, while that of furan was low. The plasma-polymerized films were analyzed with X-ray photoelectron spectroscopy (XPS) and attenuated total reflection (ATR) FTIR. A certain amount of oxygen was found on the surface of the films from pyrrole and thiophene even though the monomers did not contain oxygen. The oxygen concentration of the films from pyrrole and thiophene increased gradually with time. Water in air was thought to responsible for the increase of oxygen concentration. For the film from furan, oxygen concentration was high and did not increase so much.

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Expanded poly(tetrafluoroethylene) (ePTFE) films grafted with 2-hydroxyethyl methacrylate (HEMA) were applied to a polymer support for urease immobilization. The amount of absorbed water for HEMA-grafted ePTFE (ePTFE-g-PHEMA) films prepared by the combined use of the plasma treatment and photografting increased with an increase in the grafted amount and the ePTFE-g-PHEMA films possessed high water-absorptivities. Imidazole groups were introduced to grafted PHEMA chains with 1, 1′-carbonyldiimidazole in acetonitrile, and then urease was covalently immobilized to the ePTFE-g-PHEMA films in a pH 7.0 buffer at 4°C. The activity of urease immobilized at pH 7.0 had the maximum value at the optimum pH level of 7.5 for native urease. The relative activity of immobilized urease was kept almost constant in the range below the immobilized amount of 40mg/g-ePTFE and decreased probably due to crowding of urease molecules in the grafted layers at further increased immobilized amounts. An increase in the grafted amount resulted in a decrease in the relative activity of immobilized urease because the diffusivity of the substrate urea into the grafted layer decreased. The optimum temperature of the activity for urease was shifted to 60°C from 30°C for native urease by the covalent immobilization onto the ePTFE-g-PHEMA films and immobilized urease was repeatedly usable without a considerable decrease in the activity in the regions of the pH 6.0 to 9.0 and 10 to 60°C.

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Ultrahydrophobic surface formation on materials without changes with the passage of time by plasma improvement has been successfully achieved. The contact angle with water became approximately 160°. It is very important and useful to form the ultrahydrophobic surface such as the lotus surface because it is used in various fields. We used polytetrafluoroethylene (PTFE), polymonochlorotrifluoroethylene (PCTFE), and perfluoroalkoxy (PFA) as materials and treated them by CF₄ plasma or CHF₃ plasma. In order to investigate the effects of the ions and the radicals in the plasma, the treatment apparatuses of two types were used. One (apparatus I) was the type of parallel plate electrodes and the other (apparatus II) was the induction type. The estimation of material surface characteristics was carried out by measurements of the contact angle of the material surface with water, the weight of the materials and SEM observation. In case the materials were placed on the power electrode in the apparatus I and the input power for the improvement was large, ultrahydrophobic surfaces without change with time were produced. In case of PFA, such surfaces were formed even if it was put on the earth electrode. Such surfaces were not made by using the apparatus II. It was found that the formation of ultrahydrophobic surfaces without change with time could be attained by the following methods. (1) Plasma that has fluoric ions and fluoric radicals as its composition elements should be used. (2) Sheath voltage between the plasma and the material should be large (high). The roughness on the surface and the stable bond between fluoric atoms and atoms of the material on the surface should be formed. (3) Material whose structure is suitable for becoming ultrahydrophobic should be used.

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C-S and C-S-Au compound were formed by RF plasma CVD with using methane, SF₆ and Ar mixture gas at a pressure of 0.1Torr, a discharge frequency of 13.56MHz and a discharge power of 100Watt, and a discharge duration of 30min, but C-S-Au compound was formed using gold plate set on the upper graphite discharge electrode instead of graphite plate. At the constant gas flow rate of 10 SCCM for methane and Ar, and the varying SF₆ flow rate from 2 to 25 SCCM, the refractive indexes were changed from 1.7 to 2.4 and from 2.0 to 3.7 for C-S and C-S-Au compound, respectively.

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Plasma depositions of ultra thin films from seven silicon-containing liquid monomers were investigated using a continuos wave (CW) plasma source. The deposition rate of plasma polymerized films were determined using a quartz crystal microbalance (QCM) technique while the film composition were determined spectroscopiclly using primarily X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared method (FT-IR). The wettability of the plasma-polymerized films was also investigated by measuring the contact angles of water on the film surfaces. It was observed that the C=C absorption band was not present in these films. This observation is consistent with selective polymerization through the double bond. Oxygen was present in all samples investigated and this may be attributed to the quenching of radicals in the film by reactions with oxygen when exposed to atmosphere.

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