Mechanism of Resist Pattern Collapse during Development Process

Abstract

In this study, the mechanism of resist pattern collapse during the resist development process is investigated. Resist pattern collapse occurs while the rinse liquid is being dried off. This conclusion was reached after observing the resist pattern before and after the rinse-liquid drying process. The resist pattern in the rinse liquid was observed using an atomic force microscope. The source of resist pattern collapse is the surface tension of the rinse liquid. The force increases with decreasing space width between resist patterns. To avoid the resist pattern collapse problem, the use of a low-surface-tension rinse liquid, a rinse liquid with contact angle ∼90° at the resist surface, or a rigid and highly adhesive resist material is effective.