Photoacid
Photoacids are chemical compounds which release strong acids upon photolysis, which is useful in photolithography.
An example is triphenylsulfonium triflate with the formula [(C6H5)3S][CF3SO3]. This colourless salt consists of a sulfonium cation and the triflate anion. Many related salts are known including those with other noncoordinating anions and those with diverse substituents on the phenyl rings.