Overlapping-aware throughput-driven stencil planning for E-beam lithography

E-Beam Lithography (EBL) is a maskless nano-lithography technology that creates features on a wafer by directly shooting a beam of electrons onto the wafer. Different from the current mainstream optical lithography technology, i.e. 193nm ArF immersion lithography, EBL overcomes the limit of light diffraction. As one of the most promising next generation lithography (NGL) technologies, it can achieve very high resolution even for sub-10nm technology node. However, before EBL can be used for High Volume Manufacturing (HVM), its problem of low throughput has to be solved. Character Projection (CP) with a set of pre-defined characters is thought to be an essential technology for throughput improvement. With CP, a key problem is stencil planning, which is to select and place the best characters onto the stencil such that the throughput of the system can be maximized. If the overlapping between characters are awared, the throughput can be further optimized. In this paper, we investigate this 2D overlapping-aware stencil planning problem. Experiments show that our approach can achieve significant throughput improvement and remarkable speed-up comparing with previous works.