Plasma etch of AZ5206/Cr and ZEP7000/Cr for 0.18- to 0.25-μm-generation advanced mask fabrication

Fabrication of 0.18 micrometers generation clearfield logic device photomask with plasma etch was compared with wet etch method in current 0.25 micrometers mask technology. Spatial consistency between the resist develop and plasma etch modules was critical to achieve < 25 nm CD rng manufacturable process. CD linearity for 0.6 to 3.0 micrometers lines and isolated-nested CD bias for 1.0 micrometers lines were both improved with the plasma etch process. Resist loading and proximity effect is critical for plasma etched clearfield mask and can account for up to 20 nm range of overall CD budget.