Major advances in EUV resist development

ALBANY & AUSTIN, USA: SEMATECH engineers, working closely with researchers from major resist suppliers, have demonstrated chemically amplified EUV resist (CAR) platforms that support 22nm half-pitch resolution and are close to resolving sub-20 nm half-pitch features. These significant advances are critical in moving forward the infrastructure that will prepare extreme ultraviolet lithography (EUVL) for high-volume manufacturing at 22nm half-pitch.

Resist suppliers and SEMATECH evaluated resist platforms with results demonstrating 22nm half-pitch resolution and line width roughness (LWR) with 5-6nm. Although LWR is still higher than the International Technology Roadmap for Semiconductors specification, it is expected that resist post processing and etch processes are likely to bring down LWR to a value that is acceptable on the device level for early adopters in DRAM and/or Flash applications.

“These results mark a cornerstone in the development of EUV lithography. They represent the first real 22nm resist data, building confidence for EUV as a viable technology for 22nm half-pitch lithography," said John Warlaumont, vice president of advanced technology at SEMATECH. "Partnering with resist suppliers to accelerate resist cycles of learning has been critical to bringing EUV resist readiness to this point, where EUV resists can now support 22nm half-pitch imaging. The combination of SEMATECH and resist supplier expertise has been an indispensable asset in conducting this important advanced research.”

Over the past year, significant advances in EUV resists have been enabled by SEMATECH’s EUV Resist Test Center (RTC) in Albany, NY, through its two micro-exposure tools (METs) located at the University at Albany’s College of Nanoscale Science and Engineering and University of California, Berkeley.

SEMATECH’s METs have been critical in helping the industry break the 35nm half-pitch resolution barrier in 2006. Through SEMATECH’s EUV resist development program, engineers and resist suppliers subsequently made significant progress to improve resist resolution down to 26-28nm half-pitch; now they have demonstrated 22nm half-pitch resolution.

Chawon Koh, SEMATECH’s EUV resist process engineer and resist expert leading the joint evaluation of resist platforms with resist suppliers, commented: “This achievement was deemed to be impossible by leading resist experts only a few years ago. Resist suppliers have made excellent progress in improving EUV resist resolution, thanks to access to the METs, which provide the highest resolution available worldwide among EUV optical imaging systems.”

“The focus of SEMATECH’s EUV resist development program is to engineer current CAR platforms to realize 22nm high pitch introduction and provide a fundamental understanding of EUV resist exposure mechanisms to develop new platforms,” said Stefan Wurm, EUV program manager at SEMATECH. “We believe this two-pronged approach will drive resist development to the highest level and support EUVL introduction.”