EPL proximity and Coulomb effect correction by mask bias method

The mask bias method has proved to be a suitable method for EPL proximity effect correction. However, the linewidth reduction ratio due to the backscattering energy changes if the beam blur of the pattern changes. When the beam blur due to the Coulomb interaction effect in the sub-field is not uniform, the value of the mask bias should be modified. In this paper, we discuss the proximity effect correction method, considering the Coulomb interaction distribution in the sub-field.