In this paper, we develop a novel fracturing algorithm with shot overlap that is tailored towards rectilinear
masks, such as those generated via edge based OPC software. Our proposed fracturing algorithm generates
both the location and dosage of shots given the mask layout and mask making parameters. In the first step we
heuristically cover the mask polygon with overlapping shots. Next, we incorporate the forward scattering and
resist model in a least squares problem to compute the best dosage for all shots. Finally, we update the locations
of the shot edges by computing the edge placement error between our simulated contour and the desired contour.
One unique feature of our algorithm is that it can readily trade off between edge placement error and shot
count by adjusting two input parameters. Compared to a commercially available non-overlapping shot software
package, for a 400μm×400μm micron SRAM unit with about 1 million polygons, our algorithm results in a 23%
reduction in shot count, while increasing the weighted average EPE from 0.7 to 1 nanometers.