Photopolymers and Photoresists for Electronics

The resist layer, usually a polymeric film (0.5-1.0 Xm thick) is spin-coated onto the substrates and then exposed to radiation. One of the key points for obtaining high resolution is to obtain polymers with sensitivities well adapted to the chosen type of radiation and with response speeds which allow high production rates. 

E-beam 0.01-0.02 (corresponding to an associated wavelength X) 0.5-2 X 10 Direct writing Vacuum necessary 0.1 

This chapter describes some aspects of polymeric resist materials for microlithography allowing the necessary dimensions of VLSI to he reached. 

---

Photopolymerization reactions are widely used for printing and photoresist appHcations (55). Spectral sensitization of cationic polymerization has utilized electron transfer from heteroaromatics, ketones, or dyes to initiators like iodonium or sulfonium salts (60). However, sensitized free-radical polymerization has been the main technology of choice (55). Spectral sensitizers over the wavelength region 300—700 nm are effective. AcryUc monomer polymerization, for example, is sensitized by xanthene, thiazine, acridine, cyanine, and merocyanine dyes. The required free-radical formation via these dyes may be achieved by hydrogen atom-transfer, electron-transfer, or exciplex formation with other initiator components of the photopolymer system. 

Uses Monomer for adhesives, wood and optical coatings, electronic photoresists and solder masks, and photopolymers Features Ditunctional provides low vise., good chem. resist. 

Chem. Descrip. Urethane actylate/SR 454 (PEG-3 trimethylolpropane triacrylate) blend, < 400 ppm MEHQ inhibitor Uses Urethane-acrylic for radiation and peroxide cured adhesives, coatings (metal, paper, PVC floor, wood), electronics (photoresists), inks, photopolymers... 

Uses Crosslinking agent for actylic/vinyl resins PVC plastisol comonomer (reduces initial vise, and oil extractability. and improves ultimate hardness, heat distort., hot tear strength, and stain resistance) adhesion promoter hardener used in cast acrylic sheet and rod, contact lens, elastomers, ion exchange resins, dental polymers, adhesives, coatings (paper, plastic), cosmetics, paints, sealants, photopolymers, electronics (photoresists, solder masks)... 

Uses Curing agent for radiation and peroxide cure systems incl. acrylics, adhesives (pressure sensitive, structural), coatings (glass, metal, optical, paper, PVC floor, release, textile, wood), concrete polymers, flooring, electronics (conformal, photoresists, solder masks), inks (flexo, gravure, litho, screen), paints, photopolymers Trade Names SR 454 SR 454HP... 

---