Used primarily as a photoacid generator (PAG) in photolithography, especially in semiconductor manufacturing. When exposed to ultraviolet (UV) or deep UV light, it decomposes to produce a strong acid, which catalyzes chemical changes in photoresist materials. This enables precise patterning of microstructures on silicon wafers. Commonly found in chemically amplified resists due to its high thermal stability and efficient acid generation. Also used in some cationic polymerization processes and epoxy curing systems where light-triggered initiation is required.