Model Calibration And Slit Position Effect On Full-Mask Process And Proximity Correction For Extreme Ultra-Violet Lithography

Extreme ultra-violet (EUV) lithography is a promising solution for semiconductor manufacturing for the 1Xnm node and beyond. Due to the mask shadowing effect and strong flare, process and proximity correction (PPC) is required for EUV lithography even though the k1 factor is much larger than that in current 193nm immersion lithography. In this paper, we will report a procedure of model calibration and full-mask PPC flow for EUV lithography. To calibrate the EUV model, identical test structures are placed at various locations on the mask across the slit direction. Slit position effect, including mask shadowing effect, will be investigated at different locations. The wafer is patterned with a 0.25 NA EUV scanner and measured with CD-SEM for process evaluation and PPC model calibration. The EUV model is verified by wafer measurements. A PPC flow with mask shadowing effect compensation and model-based flare compensation is introduced to perform full-mask correction for the BEOL flow at 30nm HP L/S for the 16nm technology node. The slit position effect on PPC is investigated through post-PPC verification.