Novel OPC and DfM methodology for 3D memory device

Abstract

Novel optical proximity correction (OPC) and design for manufacturability (DfM) methodology for threedimensional (3D) memory device is proposed to overcome emerging hotspot issues caused by larger process proximity effect (PPE) due to unavoidable high-aspect patterning process. To realize robust pattern formation for lithography and reactive-ion etching (RIE) processes, the following methodologies are introduced: i) OPC is carried out by using averaged or designed optics not ideal to make robust pattern formation for optical variation of exposure tool, ii) lithography compliance check (LCC) is done under the worst optical condition to detect hotspots induced by optical variation of exposure tool, and modification of layout and OPC condition is performed to remove hotspots, iii) hotspots induced by RIE process are checked by using etching simulation with empirical RIE model, and modification of layout, PPC and OPC scheme is performed to remove hotspots. In this study, it is confirmed that our proposed novel OPC and DfM methodology is promising for robust pattern formation in upcoming 3D memory device.