Inverse lithography (ILT) is a pivotal technology for mask optimization in advanced semiconductor lithography mask correction. It has gained popularity since the advent of multi-beam mask writers and has evolved in complexity. Siemens Digital Industries Software has been a leader in this field, offering one of the first commercial tools for mask optimization. Siemens' Calibre pxOPC tool allows OPC engineers to input target designs, lithographic conditions, and style settings. Utilizing a large-scale, distributed solver, Calibre pxOPC optimizes the entire mask image, including both main features and sub-resolution assist features (SRAFs), to achieve ideal mask optimization.
Calibre pxOPC works natively in the curvilinear space, simplifying computation and enhancing performance. Future plans for Calibre pxOPC include integration into memory-specific flows (MEMOPC), improved tile-boundary handling, new curvilinear SRAF approaches, and GPU acceleration for enhanced runtime performance.
Calibre pxOPC is designed to address the most challenging lithographic problems in advanced manufacturing nodes, ensuring consistency and efficiency in mask optimization.