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The use of Inverse Lithography (ILT) in semiconductor manufacturing has been driving the need for curvilinear (CL) mask shapes. CL shapes improve wafer critical dimension (CD) process window through focus, reduce mask error enhancement factor (MEEF) and enable fully utilizing mask rule checker (MRC) specs to guarantee the best OPC correction on challenging corner-to-corner (CTC) and end-to-end (ETE) 2D geometries. The insertion of Multibeam (MBM) writers in mask high volume manufacturing (HVM) enables patterning complex ILT shapes with high CD control and mask fidelity. Additionally, the MBM tool’s capability to use high dose on low sensitivity resist to improve resolution without any write time penalty enables realizing the complex mask shapes from the optical proximity correction (OPC) tool with high accuracy. However more complex CL mask shapes lead to an explosion in the vertex density (vertices/um^2) and file size at the mask shop vs. Manhattan corrections. This talk will review the benefits from CL corrections and present data collected at Intel mask operations (IMO) that outline challenges in processing CL masks through different modules including mask data prep (MDP), beam fracture, inspection and CD Metrology. A path for significant file size reduction with the new MULTIGON record extension to the P39 OASIS file format will be reviewed. MULTIGON insertion involves significant changes in the mask making ecosystem that includes electronic tool design (EDA) tools, MBM writers and inspection tools. A timeline for MULTIGON insertion aligned with the vendors would be reviewed with a goal of enabling MULTIGON in HVM in 2024.
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