The Effect of an Organic Base in Chemically Amplified Resist on Patterning Characteristics Using KrF Lithography

Abstract

A new resist system composed of an SEPR chemically amplified (CA) positive resist and an N-methyl pyrrolidone (NMP) organic base has been developed for KrF excimer laser lithography. Using 0.30-µ m l&s patterns formed with KrF stepper, we studied the effect of contamination from substrate films of plasma chemical vapor deposition silicon dioxide (P-CVD SiO 2 ), low pressure CVD silicon nitride (LP-CVD Si 3 N 4 ) and reactive sputtered titanium nitride (TiN), and of airborne contamination under the condition of an 8-ppb of ammonia. The results clarify the new resist system reduces the effect of substrate film as well as airborne contamination. The new resist system enables us to form fine patterns on any substrate and attains more than one hour post-exposure delay without overcoat and undercoat films.