A Cost-Driven Lithographic Correction Methodology Based on Off-the-Shelf Sizing Tools

As minimum feature sizes continue to shrink, patterned fea-tures have become significantly smaller than the wavelength of light used in optical lithography. As a result, the require-ment for dimensional variation control, especially in critical dimension (CD) 3σ, has become more stringent. To meet these requirements, resolution enhancement techniques (RET) such as optical proximity correction (OPC) and phase shift mask (PSM) technology are applied. These approaches re-sult in a substantial increase in mask costs and make the cost of ownership (COO) a key parameter in the comparison of lithography technologies. No concept of function is injected into the mask flow; that is, current OPC techniques are obliv-ious to the design intent, and the entire layout is corrected uniformly with the same effort. We propose a novel mini-mum cost of correction (MinCorr) methodology to determine the level of correction for each layout feature such that pre-scribed parametric yield is attained with minimum total RET cost. We highlight potential solutions to the MinCorr prob-lem and give a simple mapping to traditional performance op-timization. We conclude with experimental results showing that substantial RET costs may be saved while maintaining a given desired level of parametric yield