Product Briefing Outline: ASML has introduced three new extensions for TWINSCAN NXT platform that improve imaging, overlay and productivity. The extensions enable chipmakers to manufacture smaller, faster chips more cost-effectively. The first NXT:1950i system shipped in 2009 and today more than 80 systems are in use by chipmakers around the world manufacturing current state-of-the-art devices at resolutions of 45- to 32-nm.
Problem: To continue to follow Moore’s Law by shrinking chip dimensions beyond 32-nm with 193-nm immersion scanners, chipmakers need to employ double-patterning lithography. Double-patterning is a process that requires critical chip layers to be split in two and imaged over two steps. To do this in a cost-effective manner, chip makers need high productivity lithography machines which at full speed can stay within tighter tolerances for imaging and overlay required by double patterning lithography. Manufacturing 22-nm devices will require much more accurate imaging and overlay performance, while increasing productivity to mitigate costs.
Solution: ASML has introduced ‘FlexWave’ programmable wavefronts. Just as ‘FlexRay’ customized illumination provides virtually unlimited source tuning within the illuminator, FlexWave allows programmable wavefronts within the lens. FlexWave’s application-specific wavefront correction provides control to reduce both the aberration fingerprint of the projection optics and lens heating effects. ASML has also developed ‘Reticle Control’ that compensates for reticle heating typically found in high dose layers with low transmission reticles. This enhancement features a new sensor that measures a reticle’s temperature profile throughout its first production lot, then predicts the resulting thermal expansion per exposure and calculates feed-forward corrections to lens and stage parameters. ASML has also addressed the cost of lithography by increasing system throughput on the NXT:1950i by 15-20%. A Performance Enhancement Package, PEP NXT:1950i, includes both hardware and software improvements that extend NXT:1950i throughput from 175 to 200 wafers per hour at 125 shots, and even 230 wafers per hour at 96 shots.
Applications: 22nm and below double patterning.
Platform: The TWINSCAN NXT:1950i has a numerical aperture (NA) of 1.35. In-situ measurement and correction of optic aberrations enable maximum imaging performance for each wafer exposed when imaging at very low k1.
Availability: All three NXT enhancements are also available as field upgrades. FlexWave and Reticle Control are available now and PEP NXT:1950i will be available in Q3 2011.