The first day of the conference was an exciting one for me. I was honored and humbled to become the 6th winner of the Frits Zernike Award for Microlithography. I’ll have more to say about this later, but there is no doubt that this moment was one of the highlights of my career.

The plenary talks were exceptional this year, especially the last two. Here are some of my favorite phrases and quotes:

Lisa Su, Freescale: “Lithography-induced complexity”

Gilad Almogy, Applied Materials: “2009 will likely be the worst year ever for our industry.”

Bernie Meyerson, IBM: “Where have all the GHz gone?”
“Atoms don’t scale.”
“Scaling is dead. Moore’s Law isn’t.”
The Albany EUV alpha-demo tool “looks like you rolled an electromagnet through an automotive junkyard.”

When the conference sessions began, I attended the resist conference. It was great to witness the presentation of the first Jeff Byers Best Poster Award. I am extremely gratified to see Jeff’s memory honored in this way, though I’m sure Jeff would have shook his head in disbelief at the mere thought of such a thing! Thanks to the resist conference organizers for creating this wonderful award. At the end of the first session, just before lunch, Cliff Henderson inserted into his talk a 70th birthday recognition for Grant Willson, including beautiful collage picture of Grant and ending with a rousingly off-key rendition of the Happy Birthday song. Congratulations Grant! It’s fun to see you embarrassed.

The afternoon papers did not generate much excitement for me, and I guess I am so used to it now that I didn’t even get riled up when I saw the graphs with no numbers on the axes or the study that compared “material A” to “material B” and found, amazingly, that material A was better.

In the evening, I stood by my two posters for two and a half hours – tiring but fun. The good thing about the low attendance is that the poster session was actually manageable this year – the crowds were not so great and one could easily navigate through the isles and see the posters. Not that I did. The disadvantage of giving a poster is that you don’t get to see any of the others. Still, I had many great discussions with people who came by.

The day ended with dinner (and beer) at Gordon Biersch. A day in heaven for a lithographer.

It’s that time of year again – time to be back in San Jose for the 33rd annual SPIE Advanced Lithography Symposium. Looking back, I realize that this is the 25th consecutive Advanced Lithography (formerly Microlithography) Symposium that I have been to. That’s a lot of years! The conference has sure changed since those early days, most spectacularly in the growth of papers and attendees. In that sense, this year’s conference is harking back to a bygone era – attendance is expected to be down more than 50% from last year (due mostly to company travel restrictions). I suppose, though, that it is not fair to make such a comparison, since the number of papers is down only slightly from last year (barring an unexpected jump in the number of cancelations). It will still be impossible to see every presentation and poster that I would like!

The earliest indicator of a slow year came today, Sunday, during the short courses. Five courses were canceled and the rest had very low attendance numbers – my course drew 11 students, down from my average of 20 – 30. Still, it was a good group of students and teaching my “world according to NILS” class was fun as always.

The outlook for our industry is bleak, and yet I’m selfishly excited about this year’s symposium. I’ve been working on a fundamental understanding of line edge roughness, creating a complete stochastic model for lithography. I’ve made a lot of progress lately and I’m really looking forward to my two poster papers Monday night – some of my best work ever, I think. Let the conference begin!

The past ten years have been hard on the magazine publishing industry, with 2008 a particularly bad year. No one’s quite sure how web-based publishing will affect print in the end, but there have already been many casualties. Last month one of my favorite trade publications, Microlithography World, bit the paper-shredding dust. MLW was the brain-child of Sid Marshall, the editor of Solid State Technology (a magazine founded by his father, Sam Marshall) until that magazine’s purchase by PennWell. First published in January, 1992, MLW was thin and ran quarterly, but it filled a void in the publishing world, which previously didn’t offer a dedicated space for lithography publications.

As the magazine was launched, Sid contacted me about publishing a paper in this new quarterly. Instead, I proposed a more radical idea: I would write a short tutorial paper for every edition of the magazine. Sid agreed, and in January, 1993 the first “Lithography Tutor” article appeared. Here is the introduction I wrote for that first article:

“Welcome to The Lithography Tutor, a new regular feature of Microlithography World. As the name implies, the purpose of this column is to present lithography information in a tutorial format. Each issue of Microlithography World will carry a two to three page edition of this continuing series on the basic principles of optical lithography. To give you a brief outline of what is to come in the next several issues, we’ll begin by studying optics. How is an image formed by a projection optical system (stepper or scanner)? What is the influence of wavelength, numerical aperture, coherence, illumination? Then, we will examine how this image propagates through the photoresist (including absorption and standing waves) and exposes the resist. Finally, the properties of development will be discussed. From here, we can begin discussing lithography as a system, define what is meant by lithographic quality, and look for ways to optimize our lithography system to maximize its quality. All this in two to three pages per issue! I’m not sure how long it will take to get through all of these topics, but I’ll certainly have fun writing this column. I hope you will enjoy reading it.”

And I did have fun writing my column. I looked forward to it each quarter, since it forced me to figure out not just how to present information, but how to explain it. It was also a great pleasure working with the editor who took over for Sid, Marc Levenson (a.k.a. “M. David”).

In the spring of 1996 the column was renamed The Lithography Expert – it seems the publisher liked the idea of having an expert write its articles rather than a mere tutor (I guess that means I was promoted, though my pay remained the same: nothing). When the last MLW came out in November 2008, I had written a total of 63 Tutor/Expert articles – quite a run! Much of the information and explanations found in those articles made it into my textbook, Fundamental Principles of Optical Lithography, so that even as MLW disappears, the spirit of the Lithography Tutor/Expert lives on. Still, I’ll miss the deadline pressure to find another interesting lithography topic amenable to a good 2-page explanation. Maybe I’ll have to write another book to fill that need in me to explain.

At the beginning of this year, IEEE Spectrum asked me to write an article about double patterning for the general electrical engineering audience. Sounding like fun, I agreed. The editor then warned me to think about the process as a “collaborative” writing experience with the editors of the magazine. That has certainly proven to be true, since the final article bears little resemblance to the first draft I submitted in May. Still, the result, I think, serves the basic purpose of explaining to a general technical reader what is going on in advanced lithography and why.

The article is entitled “Seeing Double” and appeared in the November issue of IEEE Spectrum.

Grant Willson, friend and fellow professor at the University of Texas at Austin, has won just about every award that the chemistry profession has to offer. And since his work straddles the fence between science and engineering, he’s won just about every award that the chemical engineering profession has to offer as well. Add to that his accolades while at IBM and the respect of the lithography community (winning the Frits Zernike award, its highest honor), and it would be fair to say that his accomplishments have received some well-deserved recognition.

Last month, though, Grant’s recognition rose to a new level. He was one of eight recipients of the 2007 National Medal of Technology and Innovation, our nation’s highest honor for technological achievement. In October he was presented his award by President Bush in a White House ceremony.

His wife Debbie sneaked a video recording of the presentation on her digital camera. Grant shakes the President’s hand and then tells him a joke, getting him to laugh. Then after the reading of the citation [“for creating lithographic imaging materials and techniques that have enabled the manufacture of smaller, faster and more efficient micro-electronic components”] he and Bush both pose doing the “hook ‘em horns” hand gesture. Awesome.

Congratulations, Grant.

Early this year, SPIE (the optical engineering professional society) asked me to write an article for their magazine devoted to careers in optics, SPIE Professional. They wanted to hear any advise I might have for people in, or thinking about entering, the field of semiconductor lithography.

I thought for a moment and then asked, “Are you sure you really want my honest opinion?” They assured me that they did, and so I wrote a short article giving my unfiltered opinion as to whether a career in lithography was a good idea. When I submitted it, I asked again, “Are you sure you want to publish this?” To their credit, SPIE wanted only my true views, with no spin or sugar coating. The article has just come out. SPIE members can access it at http://spie.org/x4274.xml (the article is called Fab Future). The print version should be in the mail soon, if it hasn’t been sent already.

Here is the tag line for the article:

The “Litho Guru” takes a dim view of lithography remaining a top dog in semiconductor manufacturing and in fueling Moore’s Law. Growth and fun are slowing.

It’s not really an upbeat assessment of the potential for a career in lithography, or the semiconductor industry in general. But then, for those of us working in that field, this is not news.

A friend and fellow lithographer, Garry Bordonaro, sent me a quote he had heard describing lithography:

“Photolithography is a mysterious mix of time-honored ingredients, chaotic chemistry, humble patience, and blind faith.”

I love it! Though I think there is more than a bit of science that gets thrown in as well, this description matches much of my experience over the last 25 years. Garry also thought that the quote was stolen from a beer label (how fitting!), so I did a little research. Sure enough, the essence of this quote can be found on some beers produced by the Magic Hat Brewing Company (www.magichat.net) of South Burlington, VT:

“The ancient ritual of brewing a distinctly rich and flavorful beer is nothing short of magic. Our mysterious mix of time-honored ingredients, chaotic chemistry, humble patience, and blind faith age into the secret brew we share in the rousing company of good spirits.”

Since I have shared both beer and lithography in the rousing company of good spirits, I find that I just can’t escape the beer-lithography connection.

The recent death of the great science fiction writer Arthur C. Clarke prompted me to recall his famous three “laws” (from the 1973 edition of his book of essays Profiles of the Future):

1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
3. Any sufficiently advanced technology is indistinguishable from magic.

The last law is a favorite in a world where very few of us have even the slightest idea how most of our essential gadgets work. But the first two laws I think are more interesting, and revealing.

In particular, the first law hits close to home for me. First, let us be clear what Clarke meant. He defined “elderly” in this context as any scientist over 30, or possibly 40 in some cases. Thus, I easily qualify as an elderly scientist, and some (who don’t quite know me well enough) might even regard me as distinguished. So I began to think about past pronouncements I’ve made as to what is “impossible” in the field of lithography. The most obvious category is next generation lithographies, where I have made many public statements of the kind “193 nm lithography forever” and “EUV will never work”. Could it be that I am a classic example of Clarke’s first law, and that I am “very probably wrong”?

I don’t think so. Let me explain why. First, I don’t think that EUV lithography is impossible. In fact, I am quite confident that the many smart people working on that technology will be able to demonstrate very high resolution with EUV and be able produce working high-end chips in the very near future. EUV lithography is not impossible, it is just uneconomical. Tool costs coupled with throughput (not to mention defects) will render EUV lithography fundamentally too expensive. The technology is certainly feasible, but the economic realities of semiconductor manufacturing are even more harsh than the realities of the limits of physics. The important question to our industry is not “Can you do it?”, but “Can you do it for a dollar?” EUV can’t, and in my expert opinion never will.

By the way, in 1999 Clarke added a fourth law: “For every expert there is an equal and opposite expert.” Keep that in mind when pondering my expert opinions on the fate of EUV lithography.

Last week I attended the 2008 International Workshop on EUV Lithography on Maui. Many people who know me are perfectly aware of my opinions on EUV lithography (a doomed technology), and thus may wonder why I was attending an EUV workshop. Did I mention it was on Maui?

Actually, my current primary research interest is line-edge roughness (most likely the ultimate limiter of resolution for optical lithography), a topic of great interest to the EUV community (since it is killing them). I gave a talk at the workshop and presented a full-day course on line-edge roughness the day before the workshop began. And I had some very useful discussions on the topic with various other attendees – that’s the point of a workshop, is it not? I also got the chance to tell everyone during a panel discussion that EUV would never make it to high volume manufacturing (I have a habit of stating the obvious, even if no one else does). All in all, great fun.

The workshop was organized by Vivek Bakshi, who was recently “redeployed” (laid-off) by SEMATECH, along with all the other SEMATECH lithographers in Austin who couldn’t stomach a move to Albany, NY. Since SEMATECH’s main product is workshops, it is not surprising that one of their excess minions would start up a business (Vivek has called his EUV Litho, Inc.) to compete. SEMATECH was not amused. They made it very clear that all suppliers receiving SEMATECH money would not participate in this renegade conference. As such, the meeting became more academic and international, with virtually none of the “we’re on track, trust us” talks that the tool vendors always give at similar SEMATECH meetings. And besides, it was on Maui.

And I still am. That’s why this post is almost a week late. I’ve acclimated to island time – what’s the hurry? I brought my wife and two daughters, as well as my parents, who celebrated their 50th wedding anniversary on Sunday. Life is good. In fact, I am now sitting on the balcony of my room overlooking the ocean drinking a coconut porter from Maui Brewing Company. From a can. Life is good, but not perfect.

Day 2 of the 3-beams conference saw many more good papers (and one exceptionally bad one – the other people in the room know which one I am talking about). I was especially fascinated with the work on metamaterials that can produce a negative refractive index. Such materials, which have been demonstrated in the past in the microwave regime, tax the scientific imagination and have led to many popular claims such as the possibility of making planar “superlenses”, invisibility cloaks, and other such sci-fi oddities. Unfortunately, it seems that the definition of what it takes to show negative refraction is slowly expanding to encompass phenomena that, while admittedly very interesting, might best be explained in another way.

Ivan Lalovic of Cymer gave a god paper on the influence of speckle on line edge roughness – a topic that needs attention. I also saw some papers on molecular glass resists, and I become more skeptical of this class of materials each time I hear about them.

At the end of the day, we all loaded up into buses and went to the Portland Zoo for the conference banquet. We were quite fortunate with regards to wind direction, otherwise appetizers and cocktails next to the elephant pens could have been very unpleasant. The dinner ended with the 14th annual micrograph contest – a fascinating blend of science and art. Past years’ winners can be found at www.zyvexlabs.com/EIPBNuG/uGraph.html, and this years winners will be posted soon. These pictures definitely confirm the site’s slogan that “A good Micrograph is worth more than the MegaByte it consumes.”