Verification of mask manufacturing load estimation (MiLE)

The design shrinking of semiconductor devices and the pattern complexity generated after OPC (optical proximity correction) have an impact on the two major cost consuming processes in mask manufacturing, EB (electron beam) writing and defect assurance. Mask-DFM (design for manufacturing) is a technique with various steps ranging from the design to the mask manufacturing to produce the mask friendly designs and to reduce the workload in the advanced mask production. We have previously reported on our system, called MiLE (Mask manufacturing Load Estimation), which quantifies the mask manufacturing workload by using the results of mask layout analyses. MiLE illustrates the benefits of mask-DFM efforts as numerical indexes and accelerates the DFM approaches. In this paper, we will show the accuracy of the workload estimation of the advanced devices by the comparison between the indexes and the process times in the actual mask manufacturing. The throughput of MiLE calculation of the production masks of a 65nm device was measured.