PEC-aware MPC for CD quality improvement

Extreme Ultraviolet (EUV) mask has Critical Dimension (CD) errors from various kinds of sources. Those errors are controlled for and corrected by proper correction methods such as fogging effect correction (FEC), loading effect correction (LEC), proximity effect correction (PEC), mask process correction (MPC) and so on. The corrections are mostly done independently. For example, conventionally CD nonlinearity has been the scope of mask process correction (MPC) and proximity effect has been that of proximity effect correction (PEC) because the interaction range considered is different from each other. But in order to improve the CD quality, we may need to consider the residual errors of PEC in MPC as well. For this purpose, we evaluated a new MPC method, named PEC-aware MPC, which considers writer's internal PEC for both model optimization and correction.