ASML throws weight behind bigger EUV masks

ASML is supportive of developing bigger EUV masks to restore the exposure field size of high-NA scanners back to full, CEO Christophe Fouquet said at the recent SPIE Photomask Technology + EUV Lithography conference (via Semiwiki). Fouquet called doubled-sized masks “a no-brainer” for the industry.

The industry standard EUV field and mask sizes are 26 by 33 millimeters and 6 by 6 inches, respectively. To make high-NA work, ASML and Zeiss opted to double the magnification in one direction, resulting in a half-sized field of 26 by 16.5 millimeters. ASML has beefed up the wafer stages to make up for the loss in throughput, but printing larger die sizes with a half-sized field still faces constraints. Images will have to be ‘stitched’ together to create full-sized chips.

The field size can be restored by doubling the mask size (6 by 12 inches). Initially, this option was rejected by the industry on the basis that it’s more cost-effective to keep the existing EUV mask infrastructure. Earlier this year, however, Intel started campaigning for bigger masks. At the time, ASML already indicated that it would support them if prompted by the industry. Samsung and TSMC haven’t publicly commented on the matter.