New Photomask Patterning Method based on KrF Stepper

摘要

To solve very low throughput of e-beam writer, a new patterning method based on stepper, photomask repeater ~(1～3), has been developed. For the KrF photomask repeater development we have modified a wafer-exposing stepper to expose photomasks. In this paper, we intended to clarify the feasibility of 0.15 μm generation mask fabrication with KrF photomask repeater. Interfield registration almost satisfied the 28 nm(3sigma) specification. Intra-field mis-registration was19 nm(3sigma) in 18 mm X 18 mm field area and so we have to use a small field size and basically improve this intra-field mis-registration. CD uniformity could not meet the 13 nm(3sigma) specification. Though the evaluated results of KrF photomask repeater process have not satisfied the specification of 0.15 IM generation mask, we have found the mask fabrication with KrF photomask repeater is feasible with optimization of field and process.