The semiconductor industry's migration to EUV for the leading-edge nodes provides significant advantages and poses new challenges for the mask writers. The mask quality requirements for the leading-edge process technology call for ILT (Inverse Lithography Technology) and curvilinear patterns to improve the attainable resolution on wafers and extend the process windows. While single-beam writers cannot handle writing arbitrary curvilinear patterns without throughput penalty, multi-beam mask writers (MBMW) can easily print such patterns without degrading their throughput5,6. However, the transition to the curvilinear mask ILT significantly increases the layout complexity, posing a challenge for data transfer and storage systems as the file sizes increase substantially1. Traditionally, multi-beam-writers have been using a mask data input format derived from OASIS P44, namely OASIS.MBW 1.0/1.2, leading to multi-terabyte layouts. We present OASIS.MBW 2.1 as an efficient data format for curvilinear ILT masks. OASIS.MBW 2.1 enables a dramatic reduction in file size and vertex-density and preserves the qualities of OASIS.MBW 1.1/1.2 as well as quick and easy adaptability for the end-users. This is achieved by allowing the use of the OASIS P39 POLYGON RECORD in addition to the other OASIS.MBW 1.x properties, creating a hybrid format between OASIS P39 and P44 that provides a minimal file size comparable to OASIS P39 for pre- and post-fracture data operations at the fabs. Consequently, OASIS.MBW 2.1 provides the optimal combination of minimized file size and minimized required CPU time, thus enabling fast processing as well as a fast transfer for all applications.
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