Positive‐tone photoresist consisting of a multifunctional acrylate resin that can be patterned after photo‐crosslinking

Abstract

A multifunctional acrylate resin having a tertiary ester structure is synthesized using a thiol‐acrylate Michael addition click reaction. By loading both a photo radical initiator and a photo acid generator into this resin, a positive‐tone photoresist, that can be patterned after photocrosslinking (PPaP), is formulated. After the thin film is irradiated with 365 nm light, radical crosslinking proceeds and a solvent resistant “frozen” film can be obtained. The frozen film works as a positive‐tone photoresist. When the frozen PPaP is irradiated with light containing a wavelength much shorter than 300 nm, the ester structure of the exposed region is decomposed by photo‐chemically generated acid and dissolved in an alkaline solution. Furthermore, a photochemical pattern transfer is achieved using the material. By performing the photo exposure on conventional photoresist patterns on the frozen PPaP underlayer, the photoresist patterns are successfully transferred to the underlayer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45871.

Debondable adhesives and their use in recycling

“…57 More recently, photoacid generators and photo radical initiators have been used for on-demand debonding of multifunctional acrylates, with acid-sensitive cross-linkers (esters, hemiacetals, carboxylates, etc. ), [58][59][60][61][62] and vinyl block copolymers including acid-reactive segments. [63][64][65][66][67][68][69][70] The latter utilises polymers such as poly (iso-butoxy-ethyl acrylate) or poly (isobornyl ester) where photoacid cleavage of the side chain occurs, forming acrylic acid moieties.…”

Double‐layer resist method to improve descum result when removing negative photoresist

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