US Patent 11835860 Resist composition and patterning process

A resist composition comprising an ammonium salt and fluorine-containing polymer comprising repeat units AU having an ammonium salt structure of an iodized or brominated phenol compound and repeat units FU-1 having a trifluoromethylalcohol group and/or repeat units FU-2 having a fluorinated hydrocarbyl group 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.