Curvilinear data representation and its impact on file size and lithographic performance

Abstract

As the industry is developing curvilinear mask solutions, some curvilinear post-OPC masks have been reported with file sizes in excess of 10 times the corresponding Manhattan post-OPC files, which can greatly impact mask data storage, transfer and processing. Some file size reduction utilizing spline fittings has been reported in mask post-processing. However, from an OPC perspective, mask post-processing is undesirable. In this study, we show that maintaining an adequate density of mask control points (MCPs) is key to achieving the desired on-wafer lithographic performance, regardless of whether the MCPs are connected by spline sections or piecewise-linear segments. Our results suggest that) may not offer clear lithographic performance or file size benefits. We will also offer some guidance for controlling piecewise-linear file size without compromising lithographic performance.