Novel base-sensitive polymers generating amino groups from their side chains in a nonlinear manner and their application to photoimaging materials

Abstract

We describe highly sensitive photopolymers consisting of a photobase generator (PBG), a basesensitive polymer, and a base amplifier that decomposed autocatalytically to release an amine molecule which resulted in the enhancement of base-catalyzed reactions of the base-sensitive polymer. Low molecular weight base molecules produced from the base amplifiers were widely diffused in the polymer film, resulting in the reduction of resolution power in the manner of ''air infection'' of low molecular weight basic species, although the photosensitivity was enhanced. To improve the performance, we have designed a novel base-sensitive polymer (1) tethering baseamplifying units that autocatalytically transform into amino groups attached to the polymer backbone. A film of 1 sensitized with PBG was decomposed autocatalytically by UV irradiation and subsequent heat treatment. This means that the base proliferation reaction of 1 proceeded regardless of its polymer structure. In addition, a film of 1 sensitized with PBG provided a positive working photoresist developable with an acidic aqueous solution and showed much higher photosensitivity when compared with conventional chemically amplified photoresists comprising PBG and base-labile polymers. Moreover, the use of base-amplifying polymer 1 led to prevention of ''air infection'', and improvement in the resolution power of photopolymers relying on base proliferation reactions when compared with base-sensitive photopolymers coupled with low molecular weight base amplifiers.

Synthesis of Amino Acid-derived Curing Reagents Containing a Disulfide Bond and Their Application to Anionic UV Curing Materials

“…1 H-and 13 C-NMR spectra were recorded using a Bruker AVANCEIII. APCI-MS measurements were performed using an AB Sciex API2000.…”

“…BAs increase concentration of base through their auto-catalytic decomposition reactions (base proliferation reactions) triggered by photo-generated bases from photo-base generators (PBGs), resulting in improvement of photosensitivity of the photo-reactive materials [8][9][10][11][12][13][14][15].…”

Base-amplifying silicone resins with photobase-generating side chains and their application to negative-working photoresists

“…To overcome this problem, we have proposed the novel concept of base‐proliferation reactions of base‐sensitive compounds, referred to as base amplifiers, that generate base molecules in a non‐linear manner by the action of a catalytic amount of base . Photosensitive polymers bearing base‐amplifying (BA) units have also been designed for photoresist formulations, taking into account the prevention of both evaporation and excessive diffusion of base molecules from resist films during post‐exposure baking (PEB), referred to as “air infection.” Nevertheless, air infection does produce amines from low‐molecular‐weight photobase generators. If photobase‐generating (PBG) units are immobilized in a resin, not only will such infection be stopped, but also the mixing process of BA polymer with PBG molecules will be prevented.…”

Preparation of base‐amplifying microcapsules and their application to photoreactive materials

“…The exponentially increased bases react with base‐reactive polymers, which results in an increase in apparent quantum yields. Various types of base amplifiers, such as 9‐fluorenylmethyl, phenylsulfonylethyl, and nitropentanyl carbamates have been designed that were used with PBGs. In addition, copolymers having both photobase‐generating and base‐amplifying (BA) units have been synthesized, followed by the development of photoreactive base amplifiers (PRBAs) that can work not only as a PBG but also as a base amplifier.…”