US Patent 11880136 Resist composition and patterning process

A resist composition comprising an ammonium salt and fluorine-containing polymer offers a high sensitivity and is unsusceptible to nano-bridging, pattern collapse or residue formation, independent of whether it is of positive or negative tone. The ammonium salt and fluorine-containing polymer comprises repeat units AU having an ammonium salt structure containing a carboxylic acid anion, sulfonamide anion, phenoxide anion or enolate anion of β-diketone, the anion containing fluorine, but not iodine and bromine, and repeat units FU-1 having a trifluoromethylalcohol group and/or repeat units FU-2 having a fluorinated hydrocarbyl group.