Stopping Mask Hotspots Before They Escape The Mask Shop

By Aki Fujimura The same types of physics-based issues that have haunted lithography for decades have started to impact mask writing as well. The increasingly small and complex mask shapes specified by optical proximity correction (OPC) that are now required for faithful wafer lithography at 28nm-and-below nodes have given rise to an increase in mask hotspots. Mask hotspots occur when the shap... » read more