Negative-type Photosensitive Polyimide Research Articles

An ultra heat-resistant polyimide formulated with photo-base generator for alkaline-developable, negative-type photoresist

An alkaline-developable and negative-type photosensitive polyimide (PSPI) based on poly(amic acid) (PAA) and a photo-base generator (PBG) has been developed by using chemical amplification method. The PAA(PDA-BPDA) is composed of p-phenylenediamine (PDA) and 4,4′-biphtalic dianhydride (BPDA), and the derived PI possesses excellent thermal and thermo mechanical stability due to the highly rigid and linear backbone. The photolithographic parameters for the PSPI including the PBG content, post-exposure baking (PEB) temperature, PEB time and the molecular weight of the PAA was investigated with the adoption of (E)-3-(2-hydroxy-4-methoxyphenyl)-1-(piperidin-1-yl)prop-2-en-1-one (HMPP) as the PBG. The PSPI based on PAA(PDA-BPDA) with a molar ratio of 0.9/1.0 between PDA and BPDA, and HMPP (15 wt% to PAA) showed a sensitivity of 142 mJ/cm2 and contrast of 0.58 when exposed to 365-nm light (i-line), PEB at 170 °C for 5 min, and developed with an aqueous solution of 2.38 wt% tetramethylammonium hydroxide and isopropanol. A clear negative 4-μm feature pattern was obtained and imidized into the PI pattern upon heating at 250 °C, confirming by scanning electron microscopy. This is the first work to utilize a highly rigid backbone with high thermal stability for PSPIs. The outstanding thermal and thermo mechanical stability manifests that developed PSPIs is highly potential in the microelectronics.

Development of Negative-type Photosensitive Polyimide, Based on Poly(amic acid)s, Photo Base Generator and Thermal Base Generator

Development of Negative-type Photosensitive Polyimide, Based on Poly(amic acid)s, Photo Base Generator and Thermal Base Generator

Development of Negative-type Photosensitive Semi-alicyclic Polyimide using a Photobase Generator

A negative-type photosensitive polyimide (PSPI) based on a semi-alicyclic poly(amic acid) (PAA) and a photobase generator (PBG), {[(4,5-dimethoxy-2-nitrobenzyl)oxy]carbonyl}2,6-dimethyl piperidine (DNCDP) has been developed. PAA was readily prepared from cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) and 4,4'-oxydianiline (ODA) in N,N-dimethylacetamide (DMAc) at room temperature, and used directly by the addition of the PBG for photo-lithography. The PSPI consisting of PAA (85 wt%) and PBG (15 wt%) showed the high sensitivity of 53 mJ/cm2 and contrast of 39.5, respectively, after exposed to 365 nm UV light (i-line) and developed with 0.238 wt% tetetramethylammonium hydroxide aqueous solution (TMAHaq) as a base-developer. A fine negative pattern with 6 μ features on a silicon wafer was obtained by a contact-printing mode and converted into a PI pattern by heating at 200 °C.

Synthesis and characterization of novel photosensitive polyimide based on 5‐(2,5‐dioxotetrahydrofuryl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic anhydride

AbstractA negative type photosensitive polyimide with alicyclic moiety (NPI) was synthesized from 5‐(2,5‐dioxotetrahydrofuryl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic anhydride and 4,4‐diaminobenzophenone by one‐step polymerization in m‐cresol. Properties of the polyimides were characterized and a photo‐crosslinking mechanism was investigated using DEPT 13C‐NMR and FT‐IR spectroscopy. The negative polyimide showed good photosensitivity on exposure to UV light from a mercury xenon lamp. The polyimide showed remarkable solubility difference after photo‐ irradiation with an exposure dose of 500 mJ/cm2. The resulting negative pattern of the photo‐cured NPI exhibited 10 μm resolution. Glass transition temperature of the photo‐crosslinked polyimide was about 307°C, which increased by 10°C compared to that of the polyimide before UV exposure. Transmittance of NPI after photo‐irradiation was about 87% at 500 nm. Copyright © 2004 John Wiley & Sons, Ltd.

Three-component negative-type photosensitive polyimide precursor based on poly(amic acid), a crosslinker, and a photoacid generator

A new negative-working and alkaline-developable photosensitive polyimide precursor based on poly(amic acid) (PAA), 4,4′-methylenebis[2,6-bis(hydroxymethyl)]phenol (MBHP) as a crosslinker, and a photoacid generator (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-2-(methylphenyl)acetonitrile (PTMA) has been developed. PAA was prepared by ring-opening polymerization of pyromellitic dianhydride with 4,4′-oxydianiline. The photosensitive polyimide precursor containing PAA (65 wt %), MBHP (25 wt %), and PTMA (10 wt %) showed a clear negative image featuring 10 μm line and space patterns when it was exposed to 436 nm light at 100 mJ·cm−2, post-exposure baked at 130 °C for 3 min, followed by developing with a 2.38 wt % aqueous tetramethylammonium hydroxide solution at 25 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 593–599, 2005

Photoreactive diimide models of benzhydroltetracarboxylic dianhydride: Synthesis, characterization and photopolymerization

AbstractThe synthesis, characterization and photopolymerization of bisimide compounds carrying a photoreactive methacryloyl group were investigated. Those photoreactive diimide models, derived from benzhydroltetracarboxylic dianhydride (1), were prepared in N‐methyl‐2‐pyrrolinone (NMP), either by a thermal or by a chemical imidization. In the thermal method, the bisimide carrying benzhydrol group was first synthesized by condensation of 1 with 4‐tert‐butylaniline at 180°C. The hydroxyl group was then chemically modified by an excess of methacryloyl isocyanate (6) in NMP. In the chemical method, a photosensitive dianhydride, derived from the reaction between 1 and 6, was prepared and then condensed with aniline at 25°C by means of propionic anhydride with triethylamine, which leads to the formation of the corresponding imide. By means of IR, the photopolymerization of the methacrylic double bond that takes place in the presence of a photoinitiator under irradiation at 365 nm was then investigated. It was found that the most effective photoinitiator for these photoreactive model compounds is the Michler's ketone/triethanolamine system. The further aim of the present investigation is to prepare novel negative‐type photosensitive polyimides.

Photoinduced Polymerization of Bisimides as Models for New Soluble Side-Chain-Substituted Negative-Type Photosensitive Polyimides

In this paper, we study the photoinduced polymerization of bisimide models for our new soluble side-chain-substituted negative-type photosensitive polyimides (PSPI) in order to better understand the polymerization behavior of the latter. These model compounds were cross-linked by UV irradiation in the solid state and in N-methyl-2-pyrrolidinone (NMP) solution. Variations in the molecular structure of the photosensitive moieties were explored to change the photosensitivity of models and of polymers. The kinetics of photopolymerization of these bisimide models was investigated by using infrared and UV techniques. The cinnamate and furylacrylate derivatives were found mainly to photodimerize, whereas the two others, acrylate and methacrylate derivatives, photopolymerize. Reaction orders of 1.5 and 2.0 were verified in the case of models but could not be determined for the polymers, due to the restriction of mobility of the photosensitive side groups on the polymer chains (solid-state irradiation) and also be...