US Patent 7498126 Photoacid generators, chemically amplified resist compositions, and patterning process

A photoacid generator has formula (1). A chemically amplified resist composition comprising the photoacid generator has advantages including a high resolution, focus latitude, long-term PED dimensional stability, and a satisfactory pattern profile shape. When the photoacid generator is combined with a resin having acid labile groups other than those of the acetal type, resolution and top loss are improved. The composition is suited for deep UV lithography.