Another Look at Stepper Lens Reduction and Field Size

摘要

It is possible to control linewidths on reticles over sufficiently large areas of reticles to provide benefit from increases in lens reduction. For some masking layers, the absolute control of dimensions is better for larger reticle field 5x reticles than for smaller field 4x reticles. The field size of critical layer steppers has an impact on the productivity of noncritical layer exposure tools that must be included in the determination of the overall lithography cost-of-ownership. Cost savings associated with greater lens reduction and reduced field size are greater for 200 mm than for 300 mm wafers. Results from a 7" mask are discussed.