I-LINE TO DUV TRANSITION FOR CRITICAL LEVELS

This paper reviews the transition from I-Line lithography to DUV litho graphy for critical levels in manufacturing using feature sizes at or below 350nm. The process latitude and cost factors for critical level lithography are reviewed. I-Line steppers and catadioptric step-and-sc an DUV systems are compared. Feature size shrink to 300nm and 250nm is presented as part of the cost of ownership evaluation. The performanc e parameters for I-Line steppers utilizing high numerical aperture, wi de field, refractive lens, and high contrast resist employing Phase Sh ift Mask (PSM) and oblique illumination is compared to DUV step-and-sc an technology using chemically amplified resist. The equipment cost co mparison is presented for I-Line steppers and catadioptric step-and-sc an systems along with a discussion of the cost impact of the optical d esign as NA and field size increase. I-Line with Phase Shift Mask vers us DUV is the basis for the cost of ownership calculation using the Se matech model for both DRAM and Logic manufacturing.