Better numerical model for shape-dependent dose margin correction using model-based mask data preparation

For the mask making community, maintaining acceptable dose margin has been recognized as a critical factor in the mask-making process. This is expected to be more critical for 20nm logic node masks and beyond. To deal with this issue, model-based mask data preparation (MB-MDP) had been presented as a useful method to obtain sufficient dose margin for these complex masks, in addition to reducing shot count. When the MB-MDP approach is applied in the actual mask production, the prediction of the dose margin and the CD in the finished mask is essential. This paper describes an improved model of mask process which predicts dose margin and CD in finished masks better compared with the single Gaussian model presented in previous work. The better predictions of this simple numerical model are confirmed with simulation by D2S and actual mask written by HOYA using JEOL JBX-3200MV.