VSB fracture optimization for mask write time reduction

Mask Data Preparation (MDP) fracture takes IC layout data and decomposes ("fractures") complex polygons into rectilinear and trapezoidal primitives suitable for mask writers. For rectilinear polygons, the total number of decomposed figures from a given polygon is bounded mathematically in terms of the polygon's reflex vertex count. Such geometric-based decomposition algorithms can be further optimized by considering parameters associated with VSB mask writers. This paper describes our efforts to reduce mask write time while maintaining CD quality by further optimizing the underlying algorithms. The optimization results are statistically analyzed with variation of shot size and sliver size. In addition, a case study is conducted to explore how sliver size specification impacts both shot count and fracturing quality.