PEC parameter optimization for EUV short-range effect utilizing MPC model calibration techniques

In Electron Beam (EB) exposure for Extreme Ultraviolet (EUV) masks, it is well known that the backscattering behavior differs significantly from conventional photomasks due to their film structure. In particular, short-range scattering derived from the Mo/Si multilayer film increases, causing the resist film to be more strongly affected within narrower range. To compensate for the error in Critical Dimension (CD), Proximity Effect Correction (PEC) in EB writer must be aware of this short-range scattering. While PEC calibration is typically done using the expertise of skilled engineers, adjusting the parameters of the multi-gaussian model significantly increases the burden on engineers due to the complexity of the phenomenon. In this paper, we introduce a method that automates the procedure of PEC parameter optimization by applying Mask Process Correction (MPC) model calibration techniques and providing feedback on backscattering components from empirically fitted model. Through demonstration of exposure experiments, we confirmed that accurate PEC optimization can be achieved by calibrating the MPC model using well-designed gauge patterns and exposure conditions.