Reaction Development Patterning Research Articles

Formation of Fine Pattern by Reaction Development Patterning Using Photo-Base Generator and Acidic Developers

Formation of Fine Pattern by Reaction Development Patterning Using Photo-Base Generator and Acidic Developers

Photosensitive engineering plastics based on reaction development patterning

Photosensitive engineering plastics as typified by photosensitive polyimides are mainly used in the electronics industry to form fine patterns for uses in which they will not be removed for a long time. However, to impart photosensitivity, it is necessary to introduce a functional group into a polymer or to use a precursor polymer, which hinders further applications of these polymers. We have developed reaction development patterning (RDP) as a method of forming a fine pattern by promoting the reaction between carboxylic acid derivatives in a polymer chain and nucleophiles in a developer selectively at the exposed or unexposed area. Since engineering plastics such as polyimide and polycarbonate inherently have carboxylic acid derivative groups in their main chain, RDP can easily impart photosensitivity to a wide range of polymers, including commercially available engineering plastics. By using RDP, it is possible to form both positive- and negative-tone patterns from the same polymer. In this review, I will describe recent developments in the study of photosensitive engineering plastics by focusing on RDP. This review focuses on recent developments in the study of photosensitive engineering plastics based on reaction development patterning (RDP). RDP is a method of forming a fine pattern by promoting the reaction between carboxylic acid derivatives in a polymer chain and nucleophiles in a developer selectively at the exposed or unexposed area. Since engineering plastics such as polyimide and polycarbonate inherently have carboxylic acid derivative groups, RDP can impart photosensitivity to various polymers, including commercially available engineering plastics. Both positive- and negative-tone patterns can be formed by using RDP.

Formation of Positive- and Negative-tone Patterns of Poly(lactic acid) by Reaction Development Patterning

Reaction development patterning (RDP) was applied to poly(lactic acid) (PLA) to realize formation of a fine pattern by a photolithography process. The RDP of PLA using an aqueous solution of tetramethylammonium hydroxide (TMAH) as a developer gave a positive-tone fine pattern. It was also revealed that addition of polyfunctional aromatic acids such as 3,5-dihydroxybenzoic acid to the film of PLA largely shortened the development time. When an alcoholic solution of TMAH was used as a developer, a negative-tone fine pattern was obtained, and pattern formation was achieved by a very short-time development without adding an acidic compound to the film.

Formation of Fine Pattern from Polyarylate-Silicone Copolymer by the Application of Reaction Development Patterning

Formation of Fine Pattern from Polyarylate-Silicone Copolymer by the Application of Reaction Development Patterning

Photosensitive Polyimide-silicone Copolymer based on Reaction Development Patterning (RDP)

Photosensitive Polyimide-silicone Copolymer based on Reaction Development Patterning (RDP)

Photosensitive poly(vinylene carbonate)s based on reaction development patterning with dilute aqueous alkaline solution

We examined positive-tone pattern formation based on reaction development patterning (RDP) using hydrolysis of carbonate groups on the side chains of vinyl polymers. Homopolymers and copolymers with carbonate groups were prepared by radical polymerization using vinylene carbonate (VCA) as a monomer. Application of RDP to the VCA homopolymer resulted in unclear positive-tone pattern because the high reactivity of the carbonate group led to insufficient difference in solubility between the exposed and unexposed areas. When we applied RDP using 5.0 wt% NaOHaq as developer to the copolymers between VCA and vinyl acetate (P(VCA–VAc)s), clear positive-tone patterns were successfully obtained. The effect of the ratio of carbonate groups in the copolymers on the development property of the RDP process was examined, and the use of a copolymer in which the ratio between VCA and VAc was 1:0.6 was found to yield positive-tone pattern with the highest contrast. Pattern formation using more dilute developer (1.0 wt% NaOHaq) was also achieved. Though conventional photosensitive polymers are required to have acidic or protected acidic groups for alkaline development, we succeeded in addition of photosensitivity to P(VCA–VAc)s, which do not have such functional groups, by using dilute aqueous alkaline solutions as developers. © 2015 Society of Chemical Industry

Utilization of Polyarylates Having Chemically Introduced Diazonaphthoquinone Structure for Reaction Development Patterning

Utilization of Polyarylates Having Chemically Introduced Diazonaphthoquinone Structure for Reaction Development Patterning

Addition of Photosensitivity to Hyperbranched Engineering Plastics based on Reaction Development Patterning

Addition of Photosensitivity to Hyperbranched Engineering Plastics based on Reaction Development Patterning

Development of Photosensitive Alicyclic Polyimides Based on Reaction Development Patterning

Development of Photosensitive Alicyclic Polyimides Based on Reaction Development Patterning

Development of Photosensitive Vinyl Polymers with Imide Group Based on Reaction Development Patterning

Development of Photosensitive Vinyl Polymers with Imide Group Based on Reaction Development Patterning

Positive-tone Pattern Formation from Vinyl Polymers with Maleimide Group by Reaction Development Patterning

Positive-tone Pattern Formation from Vinyl Polymers with Maleimide Group by Reaction Development Patterning

Photosensitive Sulfonated Polyimides utilizing Alkaline-developable Negative-tone Reaction Development Patterning

Photosensitive Sulfonated Polyimides utilizing Alkaline-developable Negative-tone Reaction Development Patterning

ChemInform Abstract: Addition of Photosensitivity to Engineering Plastics by a Novel Pattern‐Forming Method Using Reactions of the Polymers with Developers: Reaction Development Patterning

AbstractReview: 40 refs.

ポリマー／現像液間の反応を鍵とした新規画像形成法―反応現像画像形成―によるエンジニアリングプラスチックの感光化

Photosensitive polyimides have been used to form thermally and mechanically stable fine patterns utilized for such as buffer-coat layers and inter-layer dielectrics in electronic devices. Conventional photosensitive polyimides usually contain poly(amic acid)s as polyimide precursors or functionalized polyimides as their polymer component. Here, we report a novel design for preparation of photosensitive polyimides, reaction development patterning(RDP). RDP utilizes nucleophilic acyl substitution reaction of nucleophiles in developer with imide groups in polyimides as the key reaction of pattern formation, and therefore, no introduction of specific functional groups into polyimide framework is needed. In addition, RDP can afford photosensitivity to engineering plastics having carboxylic-acid-derivative linkages other than polyimide. We have developed both positive- and negative-tone RDPs. Positive-tone RDP utilizes main-chain scission of engineering plastics by amines in developer for pattern formation. Negative-tone RDP realizes higher sensitivity with smaller amount of photosensitive agent than positive-tone RDP. Application of industrially-used alkaline developer to negative-tone RDP is also achieved. Further reduction of the amount of photosensitive agent with increasing sensitivity is examined by introduction of chemical amplification mechanism to RDP.

Development of chemically amplified reaction development patterning

Various carboxylate and sulfonate esters were synthesized as acid amplifiers by reacting carboxylic acid chlorides and sulfonic acid chlorides with alcohols. The synthesized acid amplifiers were introduced into a photosensitive polyetherimide (PEI) system on the basis of reaction development patterning (RDP) composed of PEI (Ultem) and a diazonaphthoquinone compound (PC-5) as a photosensitive agent, and the availability of the resulting chemically amplified RDP (CARDP) system was examined. It was found that the amount of photosensitive agent and the exposure dose required for the formation of fine patterns were closely related to the structure of acid amplifiers. Consequently, the use of 2SCE with two sulfonate groups in a molecule enabled the formation of clear patterns with 5 wt% of the photosensitive agent and a 300-mJ/cm2 exposure dose, which achieved a sharp reduction of 30 wt% and 2000 mJ/cm2, respectively, in the amount of the photosensitive agent and exposure dose used in conventional RDP. Good thermal properties of the patterns prepared by CARDP were also indicated.

Development of Thermostable Photosensitive Polycarbonates based on Negative-tone Reaction Development Patterning

Development of Thermostable Photosensitive Polycarbonates based on Negative-tone Reaction Development Patterning

Effect of Maleimide Compounds on Pattern-forming Property of Photosensitive Polyimide Based on Negative-tone Reaction Development Patterning

Effect of Maleimide Compounds on Pattern-forming Property of Photosensitive Polyimide Based on Negative-tone Reaction Development Patterning

Examination of Pattern-forming Conditions in Negative-tone Reaction Development Patterning

Examination of Pattern-forming Conditions in Negative-tone Reaction Development Patterning

A Novel Mechanism to Afford Photosensitivity to Unfunctionalized Polyimides: Negative-tone Reaction Development Patterning

A film of commercially available polyetherimide (PEI, Ultem(R)) containing diazonaphthoquinone (DNQ) and N-phenylmaleimide (PMI) was irradiated by UV light from high-pressure mercury lamp through a photomask and developed with a solution containing tetramethylammonium hydroxide (TMAH) to give negative-tone patterns with high sensitivity. PMI was found to retard dissolution of the exposed areas. PEI was dissolved into the developer as poly(amic acid) resulted from reaction of the imide groups in PEI with OH-. PMI is considered to react with OH- in the developer to give anionic intermediates, and at unexposed areas, the intermediates would regenerate OH- by reaction with water in the developer. At exposed areas, the regeneration would be inhibited by reaction with acid generated by photo-rearrangement of DNQ, and this would be the reason for the preferential dissolution at the unexposed areas.

Photosensitive Polyesterimides Based on Reaction Development Patterning

Various soluble polyesterimides with ketone or sulfone group in main chain were prepared by a direct one-pot polycondensation of the corresponding dianhydrides and diamines in the presence of γ-valerolactone/pyridine catalyst. The polyesterimide films containing the photosensitive agent, diazonaphthoquinone compound PC-5®, gave positive patterns based on reaction development patterning (RDP) by UV irradiation and the following development with ethanolamine/NMP/H2O mixture. The relationship between the main chain structure and photosensitivity such as shape of the resulting patterns and development time was examined, and the development time dramatically decreased by marginal introduction of electron-withdrawing group in the polymer and then gradually decreased with increasing its content. The scanning electron microscopic photograph showed that the shape of the resultant patterns depended on the polymer structure.