The invention provides a
photoacid generator, a preparation method of the
photoacid generator, a
chemical amplification type
photoresist and a preparation method of the
chemical amplification type
photoresist, and relates to the field of
photoresist. The
structural formula of the
photoacid generator provided by the invention is shown in the specification, and the
photoacid generator is
sulfonium salt taking 5-tert-butyl-3-methyl-4-methylimidazo [1, 5-a]
quinoline-3, 5-dicarboxylate as an acidic unstable group. The acidic unstable group is decomposed into an acid under high-energy
radiation, the acidic unstable group is effectively decomposed into a
carboxylic acid derivative and an imidazo [1, 5-a]
quinoline derivative under the action of the acid and PDB (photolysis alkali), and the imidazo [1, 5-a]
quinoline derivative can inhibit the
diffusion rate of photoacid in the
resist, so that the resistance of the
resist is improved. Therefore, the
dissolution rate of the photoresist in the developing solution after
exposure is changed, and the problem of top loss after
exposure and development of the photoresist is further solved.