Each year Cymer gives a talk providing an update on progress on their EUV source, and this year David Brandt’s talk was on Tuesday morning. I have never been so shocked and disappointed at an SPIE presentation in my entire career. It was a mass of inaccuracies surrounded by obfuscation and wrapped in misleading statements. I am not as adept at penetrating the techno-marketing fog as the EUV customers are (who were collectively groaning during Brandt’s talk), but let me try my best to translate a few of the statements made into plain English.

The TSMC MOPA source going down was planned. This directly contradicts what Jack Chen of TSMC said yesterday, so I don’t know how to translate this one.
Multiple MOPA sources have been installed at customer locations. Installed does not mean actual wafers have been exposed.
70W has been demonstrated. Under unstated laboratory conditions, 70W was demonstrated for 6 minutes (one graph had an x-axis with the source operating time in seconds!)
A MOPA source printed five wafers at 99.9% yield. No actual wafers were harmed in this experiment. A source was run on a lab bench and its output measured. Then, using a software algorithm, the pulses were grouped into the assumed number of pulses each die would receive, and if no pulse in that group deviated in power more than the spec allowed, that die was said to yield.
A graph shows 6 hours of controlled-loop operation of a MOPA source, but without numbers on the “power output” y-axis. This graph says nothing.
We are committed to 70 wph by the end of 2014. Using ASML’s standard calculations 70 wafers per hour translates into about 100W at the intermediate focus. Thus, this statement is essentially 100W by the end of the year, similar to what Brandt said last year and the year before. While the conditions of delivering 100W remains unstated, what it certainly does not mean is the use of a 100W source integrated onto an NXE:3300 scanner at a customer site to print wafers by the end of the year.

The statement that ASML is committed is undoubtedly true. Many, many smart, hardworking, and dedicated scientists, engineers, and staff at Cymer and ASML are doing all they can to make EUV a success. David Brandt’s talk did each of these worthy folk a great disservice.

But on to the rest of the conference. I greatly enjoyed the two sessions dedicated to “SEM Simulation and Emulation”. We have had the theoretical understanding and the tools to do a much better job of extracting information from an SEM image for a long time. It is great to see a larger effort by our community to actually making that happen. I think it is possible to look at a top-down SEM image of a set of features and extract quantitatively useful information about the line-edge roughness. Maybe one day soon we will actually do this.

My favorite talk of the conference so far was given by Ricardo Ruiz of HGST entitled “Directed self-assembly: Where does the roughness come from?” It was a model of how good data and good theoretical and mathematical understanding can be combined using clear thinking to make a difficult topic not just understandable, but easily so. (Full discloser: I visited Ricardo four weeks ago and he gave me an extended version of this talk, so the mass of data he showed was probably easier for me to grasp than most). We should all strive for such a result in our presentations.

The number of directed self-assembly (DSA) talks this year is way up (I think more than double the number from last year). Progress seems to have been remarkably fast, even though the industry has not yet converged on the one or few best options for first implementation. I’m looking forward to even more DSA talks tomorrow.

The day ended for me with Will Conley and Kafai Lai’s panel on “The Battle for the 7nm Node”. Generally, evening panel discussions are a disappointing experience. Panelist break the slide count rules and try to pack an entire talk into their allotted 5 minutes, producing a mass of uncoordinated statements that make audience participation and panelist discussions nearly impossible. Not this time. The theme was fun (a jury trial, accusing each of the technical options for 7nm node lithography of being exceptionally unpleasant, which of course they are), the panelists were highly entertaining (at 9pm, it is better to be funny than data dense), and I may even have learned a thing or two. All were good. Chris Bencher rocks.

At the plenary session, it was great to see Mordy Rothschild of MIT Lincoln Labs win this year’s Frits Zernike award. Mordy and his team (he was keen to ensure that his entire team was recognized as well) made early and critical contributions to almost every element of 193-nm lithography development, including the development, with SVG Lithography, of the first full-field 193-nm scanner in 1994. (In fact, Mordy told me that his principle contact at SVG Lithography was Frits Zernike, Jr.) After 193-nm lithography went mainstream he and his team worked on 157-nm lithography. They also made the first demonstration of immersion lithography at 157-nm, and at 193-nm, validating Burn Lin’s ideas. It is ironic that these demonstrations eventually lead to the death of 157-nm lithography. But that is the way of science and technology development: good ideas are cannibalized by better ideas.

Frank Abboud became our community’s latest SPIE fellow. Congratulations to Frank, but shame on the rest of us not nominating more of our worthy colleagues.

Bill Arnold, outgoing president of SPIE and a lithographer who has attended even more Advanced Lithography conferences than I have, gave the first plenary. I enjoyed learning more about SPIE, and seeing the pictures of Bill’s year travel the world to meet many of the 18,000 SPIE members.

Joe Sawicki of Mentor Graphics gave a nice talk on the intersection of electronic design automation and lithography (or should I say, the many intersections). He gave me my first favorite quote of the conference: “Systematic defects often start off hiding as random defects.”

The final plenary presentation was the excellent talk by Dr. Akihisa Sekiguchi of Tokyo Electron Ltd on Integrated Patterning Solutions. I enjoyed the content, style, and tone of the talk. He stated the obvious, but something that we lithographers need to hear more often: Lithography-enabled scaling came to an end a few years back. Today, scaling is patterning-driven. He showed how low 193-nm linewidth roughness (LWR) has become (less than 2 nm, though I don’t trust anyone’s numbers ever since I began studying LWR metrology). He also gave a hint of an important result we should expect to see more of during the week: directed self-assembly (DSA) defect density has decreased by a factor of 100 in the last year. Wow. The tone of Sekiguchi-san’s talk was appropriately Zen-like, a lesson most lithographers should take note of during such chaotic times. I’m glad I chose to attend his talk instead of the Dali Lama’s, who was speaking at the same time in the next town over.

The technical session began in earnest with a bevy of invited speakers (alas, I could attend only one). I went to see Jack Chen of TSMC give a refreshingly honest update of the progress and challenges of moving extreme ultraviolet (EUV) lithography towards manufacturing. Although he said the “we still have a dream to simplify the process using a small wavelength”, he made it clear that the “expensive and large program” of EUV is behind schedule. Their first NXE:3300 was installed late last year using an older source. Afeter insuring that the scanner itself was working properly, they began the upgrade process to a MOPA + prepulse source, with a “target” source power of 80 W, though the initial install will give them only 30W at intermediate focus. The tool is still down and so have not yet printed any wafers using the new source. Chen also exhibited a little frustration with source power roadmaps, showing that the promise “we’ll have 100 Watts in 1-2 years” has been given every year for over 10 years.

The second important aspect of Chen’s talk was on mask defectivity. He showed that multilayer defects on the mask cannot be repaired, so that the only choice is to get mask blank defect levels below 20 defects/blank. We are not there yet. More importantly, “fall-on adder defects” have not been eliminated. Using a mask in the EUV scanner results in defects added to the mask over time. Chen did not seem confident that these defects could be eliminated, and said that a pellicle was needed.

Mark Phillips of Intel then gave a talk about the possibility of using EUV lithography as the cut lithography tool in a complimentary lithography scheme. I liked his statement (again obvious, but something we need to hear) that reduced LWR during EUV lithography must come from higher source power, not a “miracle resist”.

In the afternoon I was intrigued by a talk by A. Oshima of Osaka University showing a positron spectroscopy technique that could measure free volume in a resist. I hope to see much more measurements from this technique in future papers. And finally two talks, by Jim Thackeray of Dow and Peter de Bisschop of Imec, showed how much we still don’t understand about pattern failure caused by stochastic effects (that is, extreme LWR). Both pointed to the development step as needing more fundamental understanding – a conclusion I wholeheartedly endorse.

I was glad to be feeling better today after feeling so miserable the day before. Still, I was not able to fully enjoy the evening hospitality suites. I had only one beer and six pieces of sushi before going to bed.

For the last 20 years, my routine for the beginning of the SPIE Advanced Lithography Symposium has been the same. Fly in to San Jose on Saturday, go out for a nice dinner with friends I haven’t seen in a while, and then teach a full-day short course on Sunday. This year that routine was interrupted by a 24-hour virus that hit me Saturday night. After a very unpleasant night, I spent Sunday in bed. To all those who signed up to take my course, possibly flying in a day early and taking up a precious weekend day to learn about lithography, I sincerely apologize.

Fortunately, the 24-hour bug is on schedule, and I feel well enough to attend the conference. Registration is up nearly 10% this year, continuing the five-year trend in growth for this conference. What can we expect to see this year? Of course, we all want to hear about progress in extreme ultraviolet (EUV) lithography. I expect the same result as last year: steady, but too slow. And what about the dark horse, directed self-assembly (DSA)? Progress on DSA over the last few years has been faster than I expected. Will that be true again this year? And after the interesting announcement 10 days ago that Cannon is buying Molecular Imprints, it will be interesting to hear about progress in nanoimprint lithography (NIL). I suspect, however, we won’t hear much on that front until next year, when the Toshiba-driven NIL development project comes to fruition.

The Bet. I regularly get questions about “the bet”. Five years ago at this conference I made a bet with Vivek Bakshi about when (or if) EUV would be used in manufacturing. The details are fuzzy (there was much beer involved), and Vivek and I don’t quite agree as to what we agreed to. Vivek said he thought EUV would be ready for manufacturing in 2013 – 2014. I said no way. Thus became the bet. I now claim victory, because I remember the bet as being EUV manufacturing in 2013. He remembers EUV by 2014, and so has ten more months to go. I’m willing to concede the disagreement on date, since it does not diminish my confidence in winning. And what will I win? That, too, is a bit fuzzy. I remember betting my Lotus, but don’t quite recall what Vivek put up. I’m sure we’ll figure it out by this time next year.

The Prediction. Last year I gave the Keynote talk at the Design for Manufacturability through Design-Process Integration conference. In that talk I predicted the end of Moore’s Law. Not exactly, news, I know. After all, to quote Gordon Moore, no exponential is forever. But I was specific in my prediction. Very specific. I predicted that Moore’s Law would end on Wednesday, Feb. 26, 2014, just before the poster session. With a prediction like that, only two outcomes are possible: I will forever more be consider a prescient sage, second only to Gordon Moore himself in my tech trend spotting abilities, or I’ll look like a fool. Personally, I’m OK either way. So if you are around, please join me Wednesday at the poster session where we’ll make a toast to the end of Moore’s Law.

Let the conference begin!

The Lithography Workshop, Nov. 10-14, 2013

I’ve just returned from a week in La Quinta, near Palm Springs, California. It is a desert of stark beauty: sand and mountains and incredible sunsets, out of which cities have risen, irrigating the desert into hiding. Palm trees and golf courses, adobe homes and strip malls, the grotesque surrounded by the sublime. And this week, a lithography conference as well.

The Lithography Workshop has been held every 18 months or so since 1981. I’ve attended about five of them (my first was in 1985 I think). They are purposefully modeled after the Gordon conferences, though they are more industrial than academic. There are presentations in the morning and in the evening, with afternoons free for socializing. They are always held in vacation destinations, and probably 20% of attendees come with their spouse.

Which is why the Lithography Workshop is commonly referred to as the Lithography Boondoggle. I suppose this nickname is deserved to certain extent, but the workshops are far from being a waste. This year there were 50 talks and about 15 posters, all of which were invited (I had a poster, but also subbed for a presenter who couldn’t make it). As a result, the presenters are almost all seasoned experts, and a truly bad paper was hard to find. Without any publication of papers or presentations, the presenters are encouraged to be more open than they might otherwise be. Sure, some marketing messages crept into a few industry papers, and how can an ambitious academic help himself from indulging in self-promotion? Over all, though, the quality of the presentations was a noticeable step above most other conferences. That’s what makes it worthwhile to attend.

The downside of this all-invited format is an excessive abundance of establishment. Of the 120 attendees, a whopping six were women. I met two students, but almost everyone else looked like me – old and male and white. Granted, there is absolutely nothing wrong with looking like me (though one could aspire for better), I just don’t want everyone to look like me. It gets boring. But this is part of the nature of the Lithography Workshop. If I want to meet young, enthusiastic students I’ll go to the 3-beams conference. If I want to meet young, enthusiastic engineers just starting out in industry (as well as almost everyone else) I’ll go to the SPIE Advanced Lithography Symposium. But for a small conference full of senior lithographers, you can’t beat the Lithography Workshop.

The four plenary talks were all quite good. I especially liked hearing about Intel’s silicon photonics efforts (about to be commercialized), and learning what ARM thinks about lithography. I got an update on progress in DSA (directed self-assembly). Several people claimed DSA would go into production in 2014 (graphoepitaxy for contact holes), which shows a development pace that rivals that of immersion lithography a decade earlier. Updates from REBL and Mapper on their massively parallel electron beam lithography tools did not engender the same reaction. If DSA is a hare, multi-beam electron lithography is a tortoise. And somehow I don’t think this story will end the way Aesop intended.

Cymer and ASML gave updates on EUV lithography. I thought it was very telling when the Cymer presenter quipped that he was in front of a hostile crowd: lithographers. His presentation was mostly an overview of LPP sources, but he showed that they have achieved 50W operation for one hour, and have repeated this feat a few times. In February they had reached 40 W, so this appears to be quite slow progress. When asked about what source would be used in the currently shipping ASML NXE:3300B scanners, he repeated an obviously well-rehearsed line: we have committed to our customers to integrate an 80W source with the NXE:3300 in 2014.

So what does such a statement mean? Jos Benschop of ASML made it more clear in his presentation. There are currently 11 3300s in various stages of production. Three have gone through factory qualification and have been accepted by customers. Two have already been shipped to customer sites, and one is being packed up know, so I suspect three will have been shipped by the end of the year. These tools are being built with an older generation source (apparently the 10W version) and will be brought up at the customer site with that source. Then, when the 80W source is ready, this new source will be integrated into the 3300s in the field. From all indications, everything about the 3300 is ready except the source. Next year will be an important one for Cymer, and for ASML.

There was some good discussion about line-edge roughness (LER), always my favorite topic. I especially liked Jed Pitera’s take on LER from a material perspective rather than a lithography perspective. What are the fundamental limits? How low can LER go? I think the answer is not low enough. We are making progress on understanding LER if not on improving it.

But now my vacation, er, conference is over. I’ve caught up with several old friends, made a couple of new ones, and come away with several good ideas. The very definition of a successful conference.

Thanks to the rapid pace of Moore’s Law, it has always been hard to visualize the future of semiconductor lithography more than a few generations out. But it seems that my future vision is more cloudy than normal of late. Still, it is fun, and occasionally useful, to defy Niels Bohr (and Yogi Berra) and try to make the most difficult kind of predictions: those that are about the future.

I’ve recent published an editorial on my vision of what the future looks like for semiconductor lithography. In a word: up. To read the editorial, in the Journal of Micro/Nanolithography, MEMS, and MOEMS (JM3), here is the link:

http://nanolithography.spiedigitallibrary.org/article.aspx?articleid=1725896

The Japan Prize has released some videos of Grant Willson and Jean Frechet recieving the Japan Prize.

The award ceremony:

http://www.youtube.com/watch?feature=player_embedded&v=ksGG1DAXe9M

A Japanese-language life story of Drs. Willson and Frechet, with a review of photolithography and chemically amplified resists:

http://www.youtube.com/watch?v=zDfTaFeOLuM

The winners’ commemorative lectures:

http://www.youtube.com/watch?v=FRGUPzdmrlo

The 57th International Conference on Electron, Ion and Photon Beam Technology and Nanofabrication (EIPBN, aka three-beams, aka triple-beam) was held this week in Nashville. The conference moves to a new location each year, and I have to admit that my decision to attend is extremely dependent on its location. I had never been to Nashville before, so here I am. The attendance of 400 was down from last year, so I suspect that many enjoyed last year’s location in Hawaii better.

A word about the venue this year. It was at the Gaylord Opryland Resort, outside of town but right next to the Grand Ole Opry (and a Mall). The place is huge, with nearly 3000 rooms and numerous themed areas, and resembles a Las Vegas resort, but with country music instead of casinos. It has everything one would expect: artificial waterfalls, indoor palm trees, fountain and light shows, and plenty of shopping opportunities. And it realizes every southerner’s dream: the outdoors is air-conditioned.

Compared to this Disneified resort, the actual city of Nashville looks run down and dingy. Broadway (the equivalent of Sixth Street in Austin) is lined with dive bars and free music. I loved it. I found a group of recent PhDs with similar tastes and we managed to try quite a few local beers (Yazoo Pale Ale was my favorite) and catch some amazing music. I was glad for the opportunity the see the other famous music town in America (Nashville deserves its claim to second place, after Austin, as the Music Capital).

Thursday night was the conference banquet, and we were treated to a dinner on a Cumberland River paddle boat. In keeping with the theme, the boat was huge, and the entertainment was a Las Vegas-style review of country music. The quality of the entertainment was surprisingly good, until the last song – a jingoistic God Bless America number that was heavy on the cheese and that left the very international audience wondering how to react. But I guess it is impossible to end a country music montage without providing proof that country music fans are the best Americans.

As I say every time I write about the 3-beams conference, its value lies in its themed diversity. While I have focused in my career on lithography for high volume chip manufacturing, an unforgiving technology niche that demands ultra-high performance and ultra-low unit cost in equal measures, this conference focuses on the needs of flexible, low volume fabrication. High resolution is usually important, but the need to make only a few things rather than a billion things changes the optimization dramatically. There is no convergence to one best solution, but rather an organic and eclectic mix of possibilities. It is a broadening experience to attend.

I heard nothing earth shattering this year, and I certainly listened to some pretty bad talks. But there were a few really good ones as well. I liked Hiroshi Fukuda-san’s poster paper on analyzing LER measurements, though I didn’t understand it (I’ll need to study the written paper). I enjoyed hearing about David Czaplewski’s method for measuring electron beam lithography backscatter – an impressive show of rigorous engineering that is so frequently lacking in this field. Pieter Kruit’s progress report on Mapper did not leave me encouraged, and neither did Tony Yen’s report on EUV mask defectivity. Both areas are progressing, but too slowly.

Virtually every conference I attend produces a soap-box moment for me, and this one has been a long time coming. While I admire the many interesting approaches that researchers have tried over the years to improve resolution in optical printing, I get tired of hearing about how their latest new technique is finally “beating the diffraction limit” and enabling feature sizes that are smaller than could be had with conventional imaging techniques. The “diffraction limit” of conventional imaging is invariably described as half the wavelength (/2), and then the researcher will show an isolated feature (usually of very poor quality) with a size of /5, or possibly down to /8, as demonstration of blowing past the limits. Regardless of how interesting the approach may be, I can’t help but get riled up when I hear such language.

First, a diffraction limit of /2 is the smallest pitch that can be printed, not the smallest feature, and it assumes imaging in air, even though immersion imaging is the standard in lithography today. The smallest half-pitch that we print in lithography manufacturing today is /5 in size, using perfectly conventional imaging. And of course we make a billion features at this size for a dollar. If we want to print an isolated feature, we can easily thin that line to a size of /10, again while staying within the confines of the diffraction limit. (And this is before we start down the path of double patterning.) It is very rare when some university research project using an exotic optical approach produces something as good as, let alone better than, what is routine in the semiconductor manufacturing world. The diffraction limit defines the smallest pitch (the distance between two features) that can be printed. There is no diffraction limit to the smallest individual feature that can be made – that is just a matter of control, and chip makers are very, very good at control.

So, my advice to all you researchers looking for the next big thing in lithography: go for it. Keep doing good work, exploring new ideas, and learning about what light and nonlinear materials can do. It’s really cool stuff. But be careful when you say you are beating some limit, or doing better than “conventional” lithography, because the limits aren’t so limiting, and “conventional” lithography can do some amazing things.

And so ends my report on the 57th 3-beams conference. I gave a paper as well, and I am happy with the outcome. Now I am going back to Austin, and I mean no disrespect when I say that the barbeque and the beer and the music is better there than Nashville. I probably shouldn’t compare, because Nashville is rightly proud of what it has to offer. But I am glad to be going home.

Last week we saw the first casualty of the ASML purchase of Cymer. Ushio has announced that it is closing down its XTREME subsidiary in Germany. Now it is just Cymer and Gigaphoton still standing, hoping that they can make enough EUV photons to support at least one of them.

From the Ushio press release of May 9:

USHIO INC. today announced that it will close down the activities of XTREME technologies GmbH, a research and development company for Extreme Ultraviolet (EUV) light sources for next-generation semiconductor lithography, and consolidate the EUV light source business into a single unit in Japan and continue it for inspection and development applications in the future.

With this, the maintenance services for XTREME EUV light sources that were provided for ASML Netherlands B.V., a subsidiary of Netherland-based ASML Holding N.V., are transferred to ASML on May 9, local time.

For any lithographer in Silicon Valley that is interested, I’m calling a happy hour:

Wednesday, May 8, 5pm – ?
The Fault Line (www.faultlinebrewing.com)
Corner of Oakmead Parkway and Lakeside, Sunnyvale

We might solve the pressing problems facing lithography scaling, but we will surely enjoy a beer or two. Pass the word on to anyone you think might be interested.

The final day of the Advanced Lithography Symposium contains what is commonly referred to as the “tool” sessions, where tool makers give updates on their latest and greatest products. As such it tends to have the most commercial presentations, with all the problems that come with commercial pressures. For the EUV conference it is also the day where technology cheerleading, and skepticism, reaches a fevered pitch.

ASML described the status of their production EUV scanner, the NXE:3300B. Eleven systems are under construction, nine of which should ship to customers by the end of this year or early next year. These systems will ship regardless of the source power available, and so the most anticipated talk was given at 9 am by Cymer. To put this year’s report in perspective, one year ago Cymer was delivering a 9W (intermediate focus) EUV source to customers, claiming that a 20W source was about to be “available”, and predicting 100W by December 2012. The goal for production remains 250W. This year Cymer was “proud” to demonstrate 40W production-like performance and said sources for the 3300 had already been shipped to ASML. Let’s parse this announcement a bit.

What Cymer showed was a modified 3100 source that achieved 40W production-like performance for 6 hours one day last week, and 40W production-like performance for 6 hours one day this week. While a definite milestone, it is certainly not the same as delivering 40W performance to a customer for regular production-like use. So, in the last 12 months Cymer has doubled source power in the lab. In six months ASML will begin shipping tools with, they hope, an 80W source attached. I find it highly unlikely that this will be achieved. An 80W source should enable about 40 wafer-per-hour throughput or so, which will be fast enough to enable valuable production learning. Then Cymer will need to increase source power to 140W (and deliver that power to customers) by the end of 2014 to meet ASML’s stated goal of having EUV lithography that is producing chips at 70 wph by the end of 2014. Cymer has to beat Moore’s Law by a long shot, doubling source power twice in the next 18 months. That will be a hard job, indeed.

Next, Zeiss showed their progress and roadmap for EUV optical systems. An important question is how high can the NA go before two more mirrors are added (thus cutting the throughput in half). Their answer: 0.45. Since the NXE:3300 has an NA of 0.33, increasing the NA to 0.45 will allow the resolution to improve by a factor of about 0.73, close enough to the expected feature size reduction of 0.7 that a second generation of EUV production tools might take the technology to one more node. With off-axis illumination (and a low k1), 10-nm or 11-nm half-pitch might be possible with NA = 0.45. It will not be easy, though.

In the afternoon, the tool talks in the optical lithography conference touched on one of my pet peeves (some people claim I have too many pet peeves), so it is time to step up on the soap box again and talk about “lying with graphs”. There are many ways to lie with graphs, and most result from the practice of advocacy speech: using a graph to impress rather than inform. This is what marketing folks often do. It is not what scientists should do. Let me take as an example the topic of global warming. Hopefully everyone has seen plots of global surface temperatures that show a fairly steep rise over the last 50 years (close to 1 degree Centigrade). Now suppose you want to argue that global temperatures are not rising. One approach would be to plot the same data on a graph that has a y-axis origin of zero centigrade (or better yet, zero Kelvin). The result will be a trend that looks almost totally flat, since the variation will be hard to notice when squeezed into a few percent of the area of the graph. This technique works well whenever you want to show a flat trend in the data, regardless of the actual trend in the data.

The two laser talks, by Gigaphoton and Cymer, each displayed dozens of graphs that lie in exactly this way. Both lasers can control dose by pulse over time to within 0.2%. But to plot the data, they chose a y-axis that went from -1% to +1%, so that 80% of the y-axis range was unused. Wavelength stability, spectral bandwidth, beam position, beam profile size, divergence, and other laser metrics were plotted in the same way, sometimes using less than 10% of the y-axis range. Why even show the data if you purposely choose a y-axis that makes any data variation invisible? Obviously it is not to inform the audience. I’ve seen other talks over the years doing the same thing: wafer chuck temperature, aberrations across a slit, etc. There is a simple rule to prevent this: your data should use up 70% of the range of both the x- and y-axes. Don’t be caught lying with graphs.

And so ends another SPIE Advanced Lithography Symposium. 2012 was an interesting year in lithography. 2013 will be even more so.