A proximity effect correction program in which forward scattering is corrected by shape modification and backscattering is corrected by dose modulation is developed. The amount of the shape modification is determined in such a manlier that the full width at half maximum of the forward scattering profile is equal to the designed size. The half maximum of the forward scattering profile is equalized by the dose modulation after the amount of the backscattering is evaluated by the area density map method. This algorithm automates pattern biasing to improve the resolution and. assures the resulting pattern size is as designed. The following features are included to improve the conventional methods: The area density map is smoothed iteratively to include higher order effect. Smaller meshes are used for better discretization accuracy. Auxiliary shots are generated to refine correction units where the spatial profile of the deposited energy is steep. The corrected results of 60 nm lines are also presented.