Photoresists Based on Network Formation in UV Lithography

Abstract

Photoresists are essential for making fine patterns in LSI production. Photoresists are divided into two types, i.e., positive and negative types. The positive type photoresists are the polymers which become soluble in the developer after exposure. On the other hand, the negative type photoresists are the polymers which become insoluble in the developer after exposure. Non-chemically amplified and chemically amplified types were developed for the negative- and positive-type photoresists. The chemically amplified photoresists are highly sensitive compared to the non-chemically amplified ones. The chemically amplified photoresists are used for KrF (248 nm) and ArF (193 nm) lithography in LSI industries. The photoresists for EUV (13.5nm) lithography are also developed based on the chemically amplified concept. This review paper is focused on the negative type photoresists using the network formation.