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 hierarchical mask data processing system. The correction accuracy was examined using experimental and lithography simulation by application to test patterns of a 1 Gbit dynamic random access memory (DRAM) metal layer. In the case of the 0.16 µm rule, the standard deviation of the refined 1D OPC was reduced to 9 nm, which is 70% of the standard deviation of 13 nm of the conventional 1D OPC method. The proposed OPC system, using an engineering workstation, 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 data processing system suppressed mask data volume expansion to within 4% compared to the data volume without OPC. These results suggest that the refined 1D OPC method is useful for the correction of 1 Gbit and future DRAM devices.