5 May 2005 Process centering OPC using design intent to improve yield
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As the industry moves to 90nm and below, the size of our process windows are rapidly decreasing. The process window is often not considered during optical proximity correction (OPC) which must match the printed wafer to the original design target for a single process point. This process point is usually at 'best exposure' and 'best defocus'. The results can be verified under different defocus conditions but it is generally assumed that the printed pattern will yield well for a range of defocus and exposure conditions. At 90nm or smaller this assumption is breaking down as the final yield of products is greatly reduced due to low pattern quality under even relatively small process variations. Instead of optimizing the OPC results using a single model a multi-model approach is proposed where the pattern is optimized using two or more process points. The final printed image is optimized to both minimize the overall CD variations across a process as well as centering this variation with respect to the original target edges in CD critical areas. To maximize the benefits of this technique we also provide more freedom to OPC by making use of design intent to vary the print requirement in different areas of the design. In this paper we describe the process centering methodology and its use of design intent. To evaluate the benefits of this technique a metric is also proposed and used to quantify experimental results. Results are compared with those of a traditional OPC flow.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Michel Cote, Michel Cote, Alexander Miloslavsky, Alexander Miloslavsky, Robert Lugg, Robert Lugg, Michael L. Rieger, Michael L. Rieger, Philippe Hurat, Philippe Hurat, } "Process centering OPC using design intent to improve yield", Proc. SPIE 5756, Design and Process Integration for Microelectronic Manufacturing III, (5 May 2005); doi: 10.1117/12.600180; https://doi.org/10.1117/12.600180

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