Chemically amplified resists: past, present, and future

The chemical amplification concept is based on the use of a photochemically-generated acid as a catalyst, which indices a cascade of chemical transformations in the resist film, providing a gain mechanism. This lithographic imaging strategy invented in 1980 has been fully accepted by the microelectronics industry and implemented in manufacture of devices by deep UV lithography employing a KrF excimer laser. The resist systems currently being developed for the next generation ArF excimer laser lithography are also built on chemical amplification. This paper reviews the development, current status, and future of chemical amplification resist.