Enhanced lithography CoO model: considerations for advanced mask

Abstract

We have proposed the cost model of advanced mask and calculated the cost of advanced mask as the ratio for the 152 mm, 5x reticle cost of 64MDRAM, 0.35 micrometers design rule. The 152 mm, 5x reticle cost of 256MDRAM, 0.25 micrometers design rule is 1.6 times higher. The 152 mm, 4x reticle cost of 1GDRAM, 0.18 micrometers design rule is 3.5 times higher. The 230 mm, 4x reticle cost of 4GDRAM, 0.13 micrometers design rule is seven times higher. The reticle cost increases rapidly with each generation. Based on the calculated results of the reticle cost, we have calculated the CoO of advanced optical lithography, and compared it with those in E-beam and x-ray lithography. The cost of optical lithography is the cheapest throughout the generation, assuming the reticle lifetime of more than 1350 wafers. However, the cost of optical lithography becomes more expensive if we assume the reticle lifetime of less than 800 wafers in 0.13 micrometers design rule and 1350 wafers in 0.18 micrometers design rule, respectively.