Resist 3D model based OPC for 28nm metal process window enlargement

Abstract

28nm metal 90nm pitch is one of the most challenging processes for computational lithography due to the resolution limit of DUV scanners and the variety of designs allowed by design rules. Classical two dimensional hotspot simulations and OPC correction isn’t sufficient to obtain required process windows for mass production. This paper shows how three dimensional resist effects like top loss and line end shortening have been calibrated and used during the OPC process in order to achieve larger process window. Yield results on 28FDSOI product have been used to benchmark and validate gain between classical OPC and R3D OPC.