Sensitivity Enhancement of a Photocuring Material by Base Amplifiers.

Photoresist materials comprising photobase generators and epoxy resins bearing carboxylic acids to lead to marked enhancement of base‐catalyzed cross‐linking reactions

“…To enhance the photosensitivity of photopolymers based on base‐catalyzed reactions, Arimitsu et al proposed base amplifiers (BAs) that are autocatalytically decomposed by a base catalyst, followed by the subsequent liberation of another base catalyst . Improving photosensitivity was accomplished by utilizing BAs . Although many of these investigations for improving photosensitivity are related to additives such as PBGs and BAs, there have been few reports studying the main chain structure of epoxy resins in photopatterning materials utilizing PBGs.…”

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

“…While photosensitive materials based on base‐catalysed reactions have merit for preventing erosion of metallic substrates, photobase generators generally have low quantum yields, which leads to low photosensitivity. 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.…”

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.…”