Development of an accurate optical proximity correction system for 1 Gbit dynamic random access memory fabrication

In this paper, we demonstrate the feasibility of a refined one-dimensional (1D) optical proximity correction (OPC) method incorporated into a hierarch ical mask data processing system. The correction accuracy was examined usin g experimental and lithography simulation by application to test patterns o f a 1 Gbit dynamic random access memory (DRAM) metal layer. In the case of the 0.16 mu m rule, the standard deviation of the refined 1D OPC was reduce d to 9 nm, which is 70% of the standard deviation of 13 nm of the conventio nal 1D OPC method. The proposed OPC system, using an engineering workstatio n, succeeded in correcting the metal layer in a miniature model of a 1 Gbit DRAM within 2-4 days. Well-designed hierarchical management in the mask da ta processing system suppressed mask data volume expansion to within 4% com pared to the data volume without OPC. These results suggest that the refine d 1D OPC method is useful for the correction of 1 Gbit and future DRAM devi ces.