EUV is born
EUV constitutes a major departure from today's tools. It uses a 13.5-nm wavelength, and the processing steps take place in a vacuum chamber. The optical elements are basically defect-free mirrors that reflect light by means of interlayer interference.
At one time, EUV was supposed to be ready for production at the 65-nm node, but the technology remains delayed. And the cost-of-owership (COO) equation remains a concern, as an EUV ''photo-cluster’’ sells for $120 million today, compared to $70 million for today’s optical ''photo-cluster,” according to Globalfoundries’ Levinson.
ASML, Canon Inc., and Nikon Corp. were the three prospective EUV scanner makers. Recently, Canon has dropped out of the leading-edge lithography race.
The two remaining vendors, ASML and Nikon, have different strategies. ASML is pushing hard to bring EUV to the 22-nm node, but Nikon believes that the technology will not be ready until the 16- or 11-nm nodes. ''Nikon anticipates a delay in EUV ecosystem readiness,’’ said Yuichi Shibasaki, general manager of the Next Generation Development Department for Nikon, at SPIE.
Nikon has also been developing an EUV tool, dubbed the EUV1, a production system that is reportedly expected to ship in 2012 or so.
ASML’s strategy is clear. Like its 193-nm immersion strategy, the company is shipping pre-production EUV tools to customers early-and before Nikon. Customers gain experience on ASML’s EUV tools, thereby hoping to lock Nikon out of the market.
So far, ASML has shipped two alpha EUV tools, including one to Albany Nanotech and another to IMEC. ASML has recently shipped its first standalone, pre-production EUV tool-the NXE:3100-to Samsung Electronics Co. Ltd.
ASML has just shipped another one to IMEC. In total, the company has six orders for NXE:3100. The company has several orders for the NXE:3300, the first, production-worthy machine that is expected to ship in the first half of next year.
The NXE:3100 is said to have a resolution of 27-nm
, a numerical aperture (NA) of 0.25, a field size of 26-nm, an overlay of 4-nm and flare at less than 5 percent. The tool sells for nearly $100 million a unit.
The stated goal of the tool is to have an overall throughput of 60 wafers an hour by year’s end. But right now, the tool has a throughput of only 5 wafers an hour. EUV tools need some 200 Watts of power to process 100 to 150 wafers an hour. At present, the current EUV tool from ASML is only running at about 10 Watts.
Analysts believe ASML has done a commendable job in getting the EUV tool ready. Now, the company-and EUV customers-are waiting on the power sources, which are being developed by several third parties.
ASML appears to be patient with the power source vendors despite the issues. ''We have three vendors working full throttle,’’ said Martin van den Brink, executive vice president and chief product and technology officer for ASML.
ASML has two power source suppliers for the NXE:3100 tool: Cymer Inc. and Ushio Inc. Cymer has devised a power source based on laser-produced plasma (LPP) technology. At present, Cymer’s LPP source is running at a sustained power of 11 Watts, according to ASML.
Rival Ushio is developing a power source based on electric discharge technology. At present, the source has demonstrated 12 watts of power, according to ASML. Another vendor, Gigaphoton Inc., has demonstrated 20 Watts of power.
''On the plus side, Cymer has already shipped four EUV sources to customers and preparing to ship a fifth one, with initial feedback from Samsung (who began initial wafer patterning in December 2010) being mixed–the patterning is good, but throughput is poor,’’ said C.J. Muse, an analyst with Barclays Capital, in a report.