Sematech engineers advance EUV resist technology to 22-nm
The focus of Sematech’s EUV resist development program is to engineer current chemically amplified EUV resist platforms to realize 22-nm high pitch introduction and provide a fundamental understanding of EUV resist exposure mechanisms to develop new platforms. The research group believes this approach will drive resist development to the highest level and support EUVL introduction.
By Ann Steffora Mutschler, Senior Editor -- EDN, August 12, 2008
In a critical step toward creating the infrastructure for extreme ultraviolet lithography (EUVL) in high volume manufacturing at the 22-nm half-pitch node, engineers from Sematech have worked closely with researchers from major resist suppliers to demonstrate chemically amplified EUV resist (CAR) platforms that support 22-nm half-pitch resolution.
Sematech also reported that the teams are close to resolving sub-20-nm half-pitch features as well.
In the work, resist platforms were evaluated with results demonstrating 22-nm half-pitch resolution (pictured left), favorable photospeed of 15 mJ/ cm2 and line width roughness (LWR) with 5 to 6 nm. Sematech noted that although LWR is 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.
John Warlaumont, VP of advanced technology at Sematech explained that the results mark a cornerstone in the development of EUV lithography and represent the first real 22-nm resist data, which should build confidence for EUV as a viable technology for 22-nm half-pitch lithography. “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 22-nm half-pitch imaging. The combination of Sematech and resist supplier expertise has been an indispensable asset in conducting this important advanced research,” he said in a statement.
Further, Sematech said that over the past year, advances in EUV resists have been allowed 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 at the University of California at Berkeley. Sematech believes its METs were critical in helping to break the 35-nm half-pitch resolution barrier in 2006. Through its EUV resist development program, Sematech engineers and resist suppliers have subsequently made significant progress to improve resist resolution down to 26- to 28-nm half-pitch; now demonstrating 22-nm half-pitch resolution.
“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,” commented Chawon Koh, Sematech’s EUV resist process engineer and resist expert leading the joint evaluation of resist platforms with resist suppliers.
In other Sematech news, late last month, global foundry UMC joined the consortium to work together on 300-mm technology.
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The linewidth roughness of 5-6 nm is only going to get worse if allowing for post-exposure bias (which would mean exposing an even smaller feature). That is because the 1:1 is the best contrast condition. If EUV failed here, it is the beginning of a massive failure.
hardly counts as 22 nm - 2008-12-8 18:03:00 PDT
