At a gathering of a few journalists last week in Wilton, Conn., ASML revealed that it has achieved first light on the NXE:3100, its pre-production EUV tool. “That means that the Cymer source is alive, up and operational,” said Noreen Harned, vice president of marketing, technology and new business at ASML. All integration and safety checks have been completed, and EUV photons are now traveling through the scanner. “It’s a very big milestone,” she said, adding, “Before the end of the year, at least one customer will have wafers out.”
The lithography toolmaker is slated to ship the first of six NXE:3100 tools, equipped with a Cymer EUV light source, by the end of the year. The final system will go out by the first half of 2011.
The first of ASML’s NXE:3100 tools, due to be shipped before the end of the year, has
achieved first light.
Each milestone passed confirms that EUV lithography is beyond science fiction, and it’s just a matter of time until the technology is used for critical layers in high-volume manufacturing. “There are no two ways about it; we are into figuring out how to make EUV lithography work in production,” Harned said.
The NXE:3100 is ASML’s next step beyond the alpha demo tool (ADT), which resides at imec in Leuven, Belgium, and the University at Albany’s College of Nanoscale Science and Engineering (CNSE) in New York. The ADT uses a discharge-produced plasma (DPP) source, and has a throughput spec of 4 wph. By the time the 3100 is shipped later this year, it is expected to have a throughput of 60 wph, based on source power of >100 W and resist sensitivity of 10 mJ/cm2.
It’s not quite there yet, though. Cymer’s laser-produced plasma (LPP) source that’s been integrated into the first 3100 tool is currently at about a third of the necessary power, according to Harned. That’s pretty standard protocol, she said, particularly when dealing with as much new technology as EUV lithography has to deal with. She said it will all be up to snuff by the time everything is bundled together and shipped off. “Cymer has things that they can do that they’ll bring and do the upgrades at our factory.”
The NXE:3100, besides having a much higher source power and throughput, improves on other points as well, including better resolution (27 nm) improved low-flare optics, a new high-sigma illuminator, and dual stages on its new EUV platform. Although ASML was able to capitalize on the Twinscan — its dual-stage platform used in XT and NXT systems from 365 to 193 nm wavelengths — an entirely new platform (dubbed NXE) had to be designed for EUV, complete with vacuum operation to handle the 13.5 nm wavelength.
The facility in Wilton, which was part of Silicon Valley Group (SVG) before it merged with ASML in 2001, focuses on the production of the reticle portion of ASML’s lithography tools. The Wilton group has shipped three of the six NXE:3100 reticle stages to Veldhoven, the Netherlands, and another — which we saw in its final testing stages on our cleanroom tour — will likely go out by the end of this week. In the Netherlands, all six systems are in build, Harned said. “One is completely built, and another one is right on its heels.”
Although ASML is building just six of the 3100s, the company has had quite a few requests for additional systems, according to Harned. “Our judgment is that the real production tool is the 3300, so we decided to do just the six systems,” she said, adding later, “They were latecomers after the others placed orders — there was enough time difference, and we had to make decisions on what we did with our supply chain and everything else.”
Needless to say, those users are clamoring for development of ASML’s NXE:3300B, which is due out in 2012. The 3300B takes resolution to 22 nm and is expected to increase throughput to 125 wph with a 15 mJ/cm2 resist and source power of >250 W. It will also include a new high-NA six-mirror lens, high-efficiency illuminator, optional off-axis illumination, and a reduced footprint.
ASML will make a concession on resist sensitivity for the 3300 tools because of the interrelatedness of resolution, linewidth roughness (LWR) and dose sensitivity, Harned said. “Since we’re going to push down on resolution, and we’re going to push down on linewidth roughness, something had to give,” she said. “Percentage-wise, we’re making a very big concession; the source supplier taking part of the burden too.”
The toolmaker is taking specific steps with its 3300 tools so that, despite the 15 mJ/cm2 resist sensitivity, they’ll still reach the at least 100 wph needed for volume production (and 150 wph for the 3300C in 2013). “If the world has a 10 mJ/cm2 resist that can still do 22 nm imaging, the machine will not limit the throughput,” Harned added. “They’ll realize much more than 100 wph.”
Ultimately, the NXE:3300 is expected to push down to 16 nm resolution with current resist capabilities, Harned said, and could push down to 11 nm with off-axis illumination. And EUV extendibility is possible beyond 10 nm with increased apertures, she added.
— Aaron Hand