Organic photoacid generators

Willson and Bowden Organic Resist Materials 1. Photoacid generation... 

The most widely employed photoactive compound that triggers the chain of chemical reactions is the photoacid generator (PAG), a molecule that upon absorption of a photon undergoes photolysis, producing Bronsted acid and other photoproducts. The acid catalyzes a chemical reaction and it is regenerated at the end of the reaction (Scheme 12.3) [ 1,4,6,11 ]. The PAG may be an ionic organic salt or a nonionic organic compound, vide infra. 

The photoacid generators used are mostly organic-based onium salts, designed to be soluble in both the casting and the developing solvent. Remarkably, some of... 

Monitoring Photoacid Generation in Thin Photoresist Films By Means of Fluorescence. Many molecules with pH-dependent fluorescence properties are known and used only in aqueous media, which essentially precludes them from resist applications. To be of use in resist applications, fluorescent molecules must be soluble in organic solvents of moderate polarity and also be compatible with polymer films... 

A novel monomer (MOBH) which has both epoxy moiety and thermally cleavable tertiary ester moiety in a molecule was synthesized and characterized. Homopolymer of MOBH and copolymers of MOBH with tert-hutyl methacrylate, tert-butoxystyrene or styrenesulfonates were synthesized. On UV irradiation the polymer films containing photoacid generators became insoluble in organic solvents. M en the crosslinked polymer films were baked at 100-220 C, they became soluble in methanol. The effective baking temperature was strongly dependent on polymer structure. The crosslinked polymers having styrenesulfonic acid ester units became soluble in water after bake treatments. 

Structure (1-100 (itn). An acidreactive modification of the polymer blend film converted part of the organic template to a sUica network through exposure to precursor vapors. The impact of the polymer blend composition on the structure of the porous silica films was examined with the stmcture of the porous silica films determined using X-ray diffraction (XRD), SEM, transmission electron microscopy (TEM), spectroscopic ellipsometry (SE), and ellipsometric porosimetry (EP). 

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