SAN JOSE, Calif. — Extreme ultraviolet (EUV) lithography is making significant progress, according to talks from Intel and Samsung specialists at an annual event here. But enough hurdles remain to prevent either company making public commitments about when it will start using the technology.
Separately, the Imec research institute announced techniques for creating a 5nm process technology using EUV to assist today’s immersion scanners. EUV is generally expected to see adoption in about 2020 on a few critical steps to avoid using more than four exposures with today’s 193nm immersion steppers.
“It’s my belief immersion will be the workhorse and EUV will be used for select layers,” said Ben Tsai, chief technologist of KLA-Tencor in a keynote opening the SPIE Advanced Lithography conference here.
Samsung suggested it is pressing forward with plans announced in October to use EUV for its 7nm node, but it has yet to say how and when. Intel reiterated its guidance of the last several years that EUV is “highly desirable for the 7nm node, but will only be used when it is ready.”
Six of eight core EUV programs are now ready or near-ready. A pellicle covering for EUV wafers is in development, and a new tool for inspecting EUV masks is the remaining hold out, said Britt Turkot who leads Intel’s EUV program.
Six of eight core EUV programs are ready to go. Source: Intel
Samsung described at the event an EUV mask inspection tool suitable for 7nm that it has been developing in house since 2012. Turkot said the lack of such tools from third parties would not prevent use of EUV but could reduce yields and increase costs.
Late last year the Korean giant produced its first EUV masks with five or fewer defects, a level making them suitable for repair, said Seong-Sue Kim of Samsung’s EUV program. “This is an amazing achievement, when I started working no EUV this looked nearly impossible,” he said.
For its part, Intel has been working on EUV masks since 1992, according to Frank Abboud who heads Intel’s overall mask operations. He vowed masks would not be a gating item for EUV and showed a new multi-beam tool for mask making that Intel designed in 2014.
Intel shipped to its wafer fab its first product-quality EUV masks last year. Its EUV mask pilot line has created multiple defect-free EUV reticles at 14, 10 and 7nm, said Turkot.
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