Diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate Research Articles

A Negative-Type Photosensitive Poly(3-hexylthiophene) with Cross-Linker and Photoacid Generator

-Conjugated polymers ( CPs) have received great attention for their potential application to electronic devices derived from their semiconductive property. Among them, poly(3-hexylthiophene) (P3HT) is of great interest because of easy preparation, high charge mobility, and high processability. Based on these benefits, P3HT has been used in a wide variety of electronic devices, such as organic solar cells, organic fieldeffect transistors (OFETs), and sensors. Generally, a micro-patterned P3HT is fabricated by the microcontact printing (mCP) method with a poly(dimethylsiloxane) stamp. However, this method requires complicated operation resulting in low productivity. To overcome this problem, direct patterning onto polythiophenes based on a photolithographic method is highly required. Direct patterning onto P3HT was demonstrated when an exposed area became insoluble due to crosslinking of an alkyl chain under irradiation with UV light. However, the cross-linking of P3HT by irradiation required a huge exposure dose. Recently, efficient patterning methods of polythiophene derivatives were reported. These methods require multi-step reactions for the preparation of matrix polymers. In this paper we propose a new, simple patterning process of P3HT by combining hexamethoxymethylmelamine (CYMEL) as a cross-linker and diphenyliodonium-9,10-dimethoxyanthracene-2-sulfonate (DIAS) as a photoacid generator (PAG). The structures of the chemicals are shown in Figure 1. P3HT was easily synthesized by oxidation polymerization and a photosensitive P3HT was prepared from a mixture of each component. In the exposed area, the aromatic rings of P3HT react with a carbocation formed from CYMEL and cross-link with each other in the presence of acids from DIAS by irradiation. This eletrophilic substitution reaction is novel to the best of our knowledge, although the similar reaction based on arylene compounds has been reported. High-resolution patterns of CPs are expected from this approach.

Negative-Working Photosensitive Polybenzoxazoles Based on Hyperbranched Poly(o-hydroxyamide)s

The negative-working photosensitive polybenzoxazole (PSPBO) composed of hyperbranched poly(o-hydroxyamide) (HBPHA), 2,6-bis(hydroxymethyl)-p-cresol (BHMP) as a cross-linker and diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) as a photoacid generator (PAG) was developed and evaluated. The HBPHA as a precursor of PSPBO was prepared by self-polycondensation of an AB2 type monomer. The acid-catalyzed cross-linking of the BHMP in the presence of strong acid such as p-toluenesulfonic acid (p-TsOH) was investigated by using DSC and TGA. The cross-linking of BHMP was accelerated in the presence of p-TsOH, whereas cross-linking was not observed until it reached 140 °C without acid. The photolithographic performance of the resist (XPR-721) formulated with 70 wt% of HBPHA, 20 wt% of BHMP, and 10 wt% of DIAS was evaluated. The resist showed high sensitivity (Eth1/2 = 56 mJ cm-2) and good contrast (γ1/2 = 4.6) with 365 nm light when it was developed in 1.19 wt% tetramethylammonium\-hydroxide (TMAH) aqueous solution at room temperature. The fine negative pattern was obtained at the 200 mJ cm-2 of i-line exposure. The patterned film was successfully converted to polybenzoxazole without any distortion by thermal treatment at 350 °C for 1 h.

Chemically Amplified Photosensitive Polybenzoxazoles Based on tert-Butoxycarbonyl Protected Hyperbranched Poly(o-hydroxyamide)s

We describe the synthesis, characterization, and lithographic performance of positive-working chemically amplified photosensitive polybenzoxazoles (PSPBOs) composed of partially tert-butoxycarbonyl (t-BOC) protected hyperbranched poly(o-hydroxyamide)s (HB-tbocPHAs) and diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) as a photo-acid generator (PAG). The HB-tbocPHAs as precursors of PSPBOs were synthesized from hyperbranched poly(o-hydroxyamide)s (HBPHAs), which were prepared by self-polycondensation of an AB 2 type monomer. A series of HB-tbocPHAs having the t-BOC content of 8-100 mol % were successfully prepared by controlling the feed amount of di-tert-butyl dicarbonate (DTBDC). HB-tbocPHAs had adequate dissolution rate in tetramethylammonium hydroxide (TMAH) aqueous solution as well as excellent solubility in common organic solvents. HB-tbocPHA having 39 mol % t-BOC group showed the optimum dissolution rate in 2.38 wt% TMAH aqueous solution and good adhesion on a silicon wafer. The thermal deprotection of the t-BOC group and conversion to polybenzoxazole (PBO) of HB-tbocPHA in the presence of strong acid such as p-toluenesulfonic acid (p-TsOH) were investigated by using FT-IR, DSC, and TGA to examine the acid effect. Both the deprotection of t-BOC groups and the conversion to PBO were accelerated in the presence of p-TsOH. The photolithographic performance of the resist formulated with HB-tbocPHA and 20 wt % of DIAS was evaluated. The resist showed 115 mJ/cm 2 of sensitivity and 2.2 of contrast with 365 nm light when it was developed in 2.38 wt % TMAH aqueous solution at room temperature. The fine positive pattern was obtained at the 200 mJ/cm 2 of i-line exposure. The patterned film was successfully converted to polybenzoxazole without any distortion by thermal treatment at 300 °C for 1 h.

A positive-working alkaline developable photoresist based on partially tert-Boc-protected calix[4]resorcinarene and a photoacid generator

A positive working low-molecular-weight photoresist based on partially t-Boc protected tetra-C-methylcalix[4]resorcinarene (t-Boc C-4-R) and a photoacid generator (PAG), diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. t-Boc C-4-Rs were prepared by the reaction of C-4-R with di-tert-butyl dicarbonate in the presence of 4-dimethylaminopyridine (DMAP). A clear film cast from a 20 wt% t-Boc C-4-R solution in cyclohexanone showed high transparency to UV above 300 nm. The appropriate t-Boc protecting ratio was about 60 mol% in view of adhesion, deprotection temperature and dissolution rate. The photoresist consisting of 60 mol% t-Boc C-4-R (95 wt%) and DIAS (5 wt%) showed a sensitivity of 13 mJ cm−2 and a contrast of 12.6 when it was exposed to 365 nm light and postbaked at 105 °C for 90 s, followed by developing with a 2.38 wt% aqueous tetramethylammonium hydroxide (TMAH) solution at room temperature. A fine positive image featuring 1.5 µm of minimum line and space patterns was observed on the film of the photoresist exposed to 40 mJ cm−2 of UV-light at 365 nm by the contact mode.

A New Positive Working Alkaline Developable Photoresist Based on a Simple Amorphous Molecule, Tri(3,5-di-tert-butoxycarbonyloxybenzyl) 1,3,5-benzenetricarboxylate and a Photoacid Generator.

A simple amorphous molecule, tri(3, 5-di-tert-butoxycarbonyloxybenzyl) 1, 3, 5-benzenetetracarboxylate (4) was prepared from 1, 3, 5-benzenetricarbonyl trichloride (3) and 3, 5-di(tert-butoxycarbonyloxy)benzyl alcohol (2). Compound 4 can form an uniformm transparent film by spin-casting on silicone wafer and the film has a good transparency above 300nm wavelength. The chemically amplified photoresist system based on 4 containing 5wt% of diphenyliodonium 9, 10-dimethoxyanthracene-2-sulfonate (DIAS) showed a sensitivity of 19mJ/cm2 and a contrast of 17 with 365nm light.

Polyimide Containing an Acetal Structure with a Photoacid Generator: A Novel Positive Polyimide Photoresist

A main-chain degradable photosensitive polyimide containing an acetal structure which degrades by the action of acid coming from a photoacid generator has been developed. Polyimides 4 were prepared by the reaction of bis(4-aminophenoxy)methane 1 and various tetracarboxylic anhydrides 2, followed by thermal treatment. In the resulting polyimides 4, 4f filmderivedfrom 4,4′-hexafluoroisopropylidenebis(phthalicanhydride)(6FDA)and 1 showedgood solubility in organic solvents and transparency to UV light. The acid-catalysed degradation reaction was confirmed by the model imide compound in the presence of p-toluenesulfonic acid. The system of the polyimide 4f containing 30 wt% of diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS), which is a photoacid generator (PAG) showed a sensitivity of 150 mJ cm−2 with 436 nm light, when it was post-exposure baked at 140°C for 30 min, followed by development with 5% tetramethylammonium hydroxide solution at 45°C.

New Negative-Type Photosensitive Poly(phenylene ether):2 Poly(2-hydroxy-6-methylphenol-co-2,6-dimethylphenol), a Cross-Linker, and a Photoacid Generator.

A negative working thermally stable and photosensitive polymer 3 based on poly(2-hydroxy-6-methylphenol-co-2, 6-dimethylphenol), 2, 6-bis(hydroxymethyl)-4-methylphenol (BHMP) as a cross-linker, and a photoacid generator diphenyliodonium 9, 10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. Polymer 3 was prepared by oxidative coupling polymerization of 2-(tetrahydropyran-2-yl)oxy-6-methylphenol 1 with 2, 6-dimethylphenol 2 in the molar ratio of 0.85 : 0.15, followed by acid-hydrolysis. Polymer 3 showed excellent transparency above 300nm in the UV-visible spectrum. The photosensitive polymer containing polymer 3 (72wt%), MBHP (18wt%), and DIAS (10wt%) showed a sensitivity (D0.5) of 7.9M/cm2 and a contrast (r0.5) of 9.3 when it was exposed 365nm light and postbaked at 125°C for 3min, followed by developing a 2.38wt% aqueous tetramethylammonium hydroxide TMAH solution at 25°C.

Three-Component Negative-Type Photoresist Based on C-Tetraoctyl-calix(4)resocinarene, a Cross-linker, and a Photo-acid Generator.

Calix[4]resocinarenes(C4-RAs), "C-tertaheptyl-calix[4]resorcinarene [C(7)C4-RA], C-tertaoctyl-calix[4]resorcinarene [C(8)C4-RA], C-tertanonyl-calix[4]resorcinarene [C(9)C4- RA], and C-tertaundecyl-calix[4]resorcinarene [C(11)C4-RA]", were synthesized by the acid-catalyzed condensation of resorcinol and alkylaldehyde. The obtained C4-RAs were well-dissolved in common organic solvents and their films were transparent above 300nm. Therefore, negative working photoresists based on C4-RAs, 4, 4′-methylenebis[2, 6-bis(hydroxymethyl)]phenol (MBHP) as a cross-linker, and a photo-acid generator diphenyliodonium 9, 10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. Particularly, the resist containing C(8)C4-RA had the dissolution property well-controlled by a conventional aqueous base developer [2.38wt% aqueous tetramethylammonium hydroxide(TMAH) solution]. Thus, the photoresist consisting of C(8)C4-RA (70wt%), MBHP (20wt%), and DIAS (10wt%) showed a sensitivity of 7mJ/cm-2 and a contrast of 6.1 when it was exposed to 365nm light and postbaked at 130°C for 3min, followed by developing with the TMAH developer at room temperature.

A New Three-Component Photoresist Based on Calix[4]resorcinarene Derivative, a Cross-linker, and a Photo-acid Generator

Abstract Calix[4]resorcinarene (2,8,14,20-tetramethylcalix[4]arene-4,6,10,12,16,18,22,24-octol, abbrev. to C4-RA) derivative (4) having p-hydroxybenzyl groups on its exterior was prepared by the condensation of C4-RA and p-(allyloxy)benzyl bromide, followed by the cleavage of allyl groups with palladium catalyst and ammonium formate. Compound 4 having high transparency to UV-light above 300 nm was considered for a new resist matrix. A three-component photoresist consisting of 4, 2,6-bis(hydroxymethyl)-4-methylphenol (BHMP), and diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) showed a sensitivity of 19 mJ cm−2 (D1/2) and a contrast of 3.0 (γ1/2) when it was exposed to 365 nm light and post-exposure baked (PEB) at 110 °C for 5 min, followed by developing with a 0.2 wt% aqueous tetramethylammonium hydroxide (TMAH) solution. A fine negative image featuring 1 μm of minimum line and space patterns was observed on film of the photoresist exposed to 40 mJ cm−2 of UV-light at 365 nm with a scanning electron microscope.

Tetrahydropyranyl-protected poly(p -hydroxystyrene) containing vinyl ether compound for three-component photopolymers

Poly(p-hydroxystyrene)s (PHSs) partially protected by tetrahydropyranyl (THP), PPT-x, containing 2,2′-bis(4-(2-(vinyloxy)ethoxy)phenyl)propane as a crosslinking agent were used as three-component photopolymers in combination with diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) as a photoacid generator. The PPT-x with a higher THP-protecting ratio was deprotected at higher temperatures than the PPT-x with a lower THP-protecting ratio. The conversions of vinyl ether compound in the photopolymer films were not related to the THP-protecting ratios in PPT-x and increased with increasing baking time. Under different THP-protecting ratios and prebaking temperatures, the PPT-x showed varying lithographic behavior between a positive-working mode and a negative-working mode. These three-component photopolymer solutions of PPT-x have good preservation stability. © 1998 John Wiley & Sons, Ltd.

Three-Component Negative-Type Photoresist Based on Calix[4]resorcinarene, a Cross-linker, and a Photoacid Generator

A negative-working photoresist based on calix[4]resorcinarene (C-4-RA), 4,4‘-methylenebis[2,6-bis(hydroxymethyl)phenol] (MBHP) as a cross-linker, and a photoacid generator diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. A clear transparent film was obtained from a 25 wt % C-4-RA solution in 2-methoxyethanol. The photoresist consisting of C-4-RA (65 wt %), MBHP (25 wt %), and DIAS (10 wt %) showed a sensitivity of 4.3 mJ/cm2 and a contrast of 2.9 when it was exposed to 365 nm light and postbaked at 120 °C for 3 min, followed by developing with a 0.1% aqueous tetramethylammonium hydroxide solution at room temperature. The mechanistic study on the formation of images is also discussed.

A Negative-Working Alkaline Developable Photoresist Based on Calix[4]resorcinarene, a Cross-linker, and a Photoacid Generator

Abstract A negative working photoresist based on calix[4]resorcinarene, 4,4′-methylenebis[2,6-bis(hydroxymethyl)phenol] (MBHP) as a cross-linker, and a photoacid generator, diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS), has been developed. A clear negative pattern was obtained when it was exposed to 365 nm UV light and postbaked at 130 °C, followed by developing with a 0.5% aqueous tetramethylammonium hydroxide solution at room temperature.

A New Negative-Type Photosensitive Polyimide Based on Poly(hydroxyimide), a Cross-Linker, and a Photoacid Generator

A negative working photosensitive polyimide based on poly(hydroxyimide) (PHI), 2,6-bis(hydroxymethyl)-4-methylphenol (BHMP) as cross-linker, and photoacid generator diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. The PHI was prepared by the ring-opening polyaddition of 4,4‘-hexafluoroisopropylidenebis(phthalic anhydride) and 4,4‘-diamino-4‘‘-hydroxytriphenylmethane, followed by thermal cyclization in refluxing xylene. The PHI film showed excellent transparency to UV light. The photosensitive polyimide containing 70 wt % PHI, 20 wt % BHMP, and 10 wt % DIAS showed a sensitivity of 70 mJ/cm2 and a contrast of 3.8 when it was exposed to 365 nm light and postbaked at 120 °C, followed by developing with a 2.5% aqueous tetramethylammonium hydroxide solution at 40 °C. The mechanistic study on the formation of images is also discussed.

Photoreactive fluorinated polyimide protected by tetrahydropyranyl (THP) group based on chemical amplification: Acid generation in polyimide film and lithographic properties

AbstractThe photochemistry of photoacid generator (PAG), diphenyliodonium 9,10‐dimethoxyanthracene‐2‐sulfonate (DIAS) and diphenyliodonium 8‐anilinonaphthalene‐1‐sulfonate (DIANS) was investigated in both alkalinesoluble polyimide (6FDA‐AHHFP) and novolak films. The quantum yields of photodissociation of DIAS and DIANS in both 6FDA‐AHHFP and novolak films. The quantum yields of photodissociation of DIAS and DIANS in both 6FDA‐AHHFP and novolak films were determined as 0.11, 0.21, 0.12 and 0.26, respectively. On the other hand, the quantum yields for acid generation from DIAS and DIANS in both of these films were 0.07, 0.18, 0.09 and 0.22, respectively, in the presence of an acid indicator. These results indicate that the values of the quantum yields of photodissociation and photoacid formation for DIAS and DIANS in 6FDA‐AHHFP film are lower than those in novolak film. In order to elucidate the lowering of the quantum yields in 6FDA‐AHHFP film, fluorescence quenchings of sodium 9,10‐dimethoxy‐anthracene‐2‐sulfonate and ammonium 8‐anilinonaphthalene‐1‐sulfonate by a model compound of polyimide was carried out in acetonitrile. The fluorescences of these two salts were efficiently quenched by the model compound with the diffusion‐controlled rate constant in acetonitrile, suggesting that a strong electron‐accepting capability of the imide carbonyl group may hinder the electron transfer process within PAG molecules in 6FDA‐AHHFP film. Although a polyimide (6F‐THP) protected by tetrahydropyranyl group is insoluble in aqueous base, 6F‐THP film containing PAG became soluble in a 2:1 mixture of 2.0 wt% tetramethylammonium hydroxide (TMAH) and methanol by exposure to 365 nm light and successive post‐exposure baking (PEB) at 120°C for 10 min. The sensitivity and contrast of 6F‐THP with DIANS after the PEB conditions mentioned above were 110 mJ/cm2 and 3.7, respectively. A high‐resolution pattern with a good profile was transferred into the 3 μm thickness of the 6F‐THP film.