PHOTOCHEMICAL PROCESSES IN PHOTORESISTS BASED ON NOVOLAC CRESOL-FORMALDEHYDE RESINS CONTAINING ELECTRON-DONATING ADDITIVES

Incorporation of donor molecules into a photoresist composition consis ting of novolac cresol-formaldehyde resin and its dissolution inhibito r, photosensitive diazonaphthoquinone sulfonate, causes photoinduced e lectron transfer from a donor to diazonaphthoquinone sulfonate in the first step of photochemical reaction. Subsequent reactions of the unst able anion radical of diazonaphthoquinone sulfonate result in formatio n of indenecarboxylic acid. When ferrocene is used as a donor, this ac id acts as a catalyst for thermal electron transfer from ferrocene to diazonaphthoquinone sulfonate, thereby amplifying the primary effect o f light.