In this paper we discuss some of the problems and solutions discovered when implementing 2-mask strong phase shifter designs for the poly gate level in logic designs. Experimental results are presented showing pattern fidelity for different reticle designs. Simulations are presented indicating the improvement in pattern fidelity that can be expected from using OPC. Simulations, PSM assignment and model-based OPC correction are performed by the Calibre WORKbench, Calibre DRC, Calibre PSMgate and Calibre OPCpro tools from Mentor Graphics. In conclusion, we show that while fairly simple designs can be used to achieve 250 nm design rules (approximately 150 nm gates), in order to achieve both pattern fidelity as well as small feature size it is necessary to use 3-layer/phase-aware model-based OPC to correct for pattern distortion for design rules of 180 nm and below (approximately 100 nm phase-shifted gates).