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Date of Award
Dissertation - NSU Access Only
Doctor of Philosophy in Computer Science (CISD)
Graduate School of Computer and Information Sciences
Michael J. Lazlo
Amon B. Seagull
According to Moore's law, the IC (Integrated Circuit) minimum feature size is to shrink node over node, resulting in denser compaction of the design. Such compaction results in more polygons per design. The extension of optical lithography to print features at a fraction of the wavelength is only possible with the use of optical tricks, like RET (Resolution Enhancement Techniques) and ILT (Inverse Lithography Technology), to account for systematic corrections needed between the mask and the wafer exposure. Such optical tricks add extensive decorations and edge jogs to the primary features, creating even larger increases in the number of polygons per design. As the pattern file size increases, processing time and complexity becomes directly proportional to the number of polygons; such increase is now becoming one of the key obstacles in the data processing flow. Polygon-based or vector-based pattern file format has been extended for the past forty years, and now its applicability to modern designs and trends is in question.
Current polygon based data flow for IC pattern processing is cumbersome, inefficient, and prone to rounding and truncation errors. The original design starts with pixelated images with maximum edge definition accuracy. The curvilinear shapes are then fitted into polygons to comply with industry standard formats, thus losing edge definition accuracy. The polygons are then converted to raster images to approximate the original intended data.
This dissertation builds on the modern advancements in digital image and video processing to allow for a new image-based format, Sequential-Pixel-Frame, specifically for integrated circuit pattern representation. Unlike standard lossy compressed video, the new format contains all the information and accuracy intended for mask making and direct write. The new format is defined to replace the old historical polygon-based formats. In addition, the dissertation proposes a more efficient data flow from tape-out to mask making. The key advantages of the new format are a smaller file size and a reduced processing time for the more complex patterns intended for advanced technology nodes. However, the new format did not offer such advantages for the older technology nodes. This is in line with the goals and expectations of the research.
Fayez Abboud. 2012. Utilizing Image-based Formats to Optimize Pattern Data Format and Processing In Mask and Maskless Pattern Generation Lithography. Doctoral dissertation. Nova Southeastern University. Retrieved from NSUWorks, Graduate School of Computer and Information Sciences. (73)