EUV is not the "best hope". It's strictly political and human emotion, not science. Too many people have too much invested in SXPL to back off now. But, ask yourself, if you ordered a PC or a piece of furniture in 2005 for delivery in 2006, and neither was delivered 7 years later, and the vendor still couldn't promise you a delivery date, at what point would you have gone elsewhere? It is completely irrational to continue to invest in this black hole, but it will continue until it is simply too embarrassing to do so. Meanwhile, optical, perhaps with a DSA assist and/or imprint will do the heavy lifting. All the invested SXPL stakeholders will continue to speak of progress and dates just beyond the horizon in the same breath.
There are alternatives. Immersion with multiple passes, direct write, and a few other technologies. But other than the multi-pass immersion, my understanding is that all of these other technologeis are also still in development. And each has its own limitations. My understanding from talking with people about this through the years is that most people that are involved in lithography see EUV as the best hope, even though the kidns are still being worked out (and probably will be being worked out for years).
A comment was made above that EUV has been under development since 2006. I suggest readers google SXPL (soft x-ray projection lithography) and find papers in the early 1990s and even late 1980s. Some marketing guy changed it's name from SXPL to EUV so it would sound more like DUV, but it didnt seem to change the wavelength. X-ray lithography is just as challenging now as it was then, after huge expenditure of money and manpower. Mr. McGrath's title "a work in progress" is an understatement. The interesting question is why. It's not as if alternatives don't exist.
Why this guys taking so much time to complete this, they should have done by now...you know once I have seen a guy who done with an <a href="http://www.aiglemed.com/mobility-aid/">Powered wheelchairs</a> project within a week.
This year at SPIE, the troubles with higher doses and higher numerical apertures were pointed out. The more advanced nodes are even harder for EUV to get in. Fortunately it was also revealed 10 nm multi-patterning may not need multiple optical immersion exposures.
EUV has been under development since 2006 and most of the foundries do not expect EUV until at least the 7nm generation, one generation beyond the 10nm Intel mentioned. That demonstrates the challenge in bringing this technology to an economic level. However, what really concerns me is now the entire industry is betting on the success of one company ASML/Cymer. I can't remember a time in the history of this industry that so much relied on one technology and one company. And even with EUV, we are likely to hit other physical limits at or just beyond th 5nm limitation. Gordon Moore has predicted the end of his own law three times that I am aware of and the last time was rather recent. He may br right this time around.
It's probably going to be a while. I should have mentioned in this posting, too, that the power source is the big issue, but there are still otherss. Since the masks will have no pellicle (they have discovered a material that is transmissive enough), mask defects and mask cleaning are a couple big issues to solve. And right now nobody knows how long the masks will last. (IMEC does have a research program going on finding ways to clean the EUV masks).
Yes, the technical side of EUV lithography seems to be making slow but steady progress. However, the cost side of EUV litho will take much longer. Eventhough it might become less expensive than quadruple patterning using immersion 193 nm lithography, it will still be prohibitively expensive for most applications for several more years.