ASML Holding NV has announced three new extensions for its popular immersion lithography semiconductor equipment TWINSCAN NXT with improvement in imaging, overlay and productivity. ASML discloses more than 80 NXT systems are in use by chipmakers around the world manufacturing current state-of-the-art devices at resolutions of 45- to 32-nm.
ASML has introduced FlexWave programmable wavefronts. FlexWave's application-specific wavefront correction provides control to reduce both the aberration fingerprint of the projection optics and lens heating effects.
The overlay gains importance when the nodes are below 90nm particularly when the nodes below 45nm. To improve overlay ASML has developed Reticle Control to compensate 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 in its paper quotes "printing 65 nm features would require an overlay of approximately 20 nm. While this still holds for non-critical layers, manufacturers are already using one-sixth and looking towards one-tenth for critical layers".
To make more semiconductor chips in less time , ASML has increased 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 semiconductor wafers per hour at 125 shots, and even 230 wafers per hour at 96 shots.
"Who says you can't get two birds with one stone," stated Dan Hutcheson, CEO, VLSI Research. "ASML has found a way not only to technically achieve 22-nm imaging, but do it in a way that is economically viable for their customers."
"ASML strives to continuously improve both the capabilities and the value of our scanners for customers," said Jan Smits, senior vice president, TWINSCAN product group at ASML. "Increasing productivity while improving imaging and overlay performance is challenging, and this is why we developed the NXT platform. The extensions announced today start to realize the platform's full potential."
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.