ASML reduces DUV overlay error to 1 nanometer

ASML’s engineers continue to improve the overlay in its most advanced immersion scanners. Since the introduction of the NXT:1950i platform in 2010, the overlay error dropped from 3 nanometers to 1.4 nanometers in the NXT:2000i two years ago. At the same time, the throughput increased from 175 to 275 wafers per hour.

“As always in our industry, we needed to do better,” says Bart Paarhuis, who presented the latest overlay results on ASML’s most recent DUV system, the Twinscan NXT:2050i, at the online Bits&Chips High Tech Systems 2021 conference. “Customers requested additional improvements. The logic manufacturers want better DUV-to-EUV matching for their 3-nanometer node and our memory customers want better overlay when patterning successive layers on the same chip by the same DUV scanner. And everyone is asking for higher productivity.”