SPIE AL07 – Day 2 (Tuesday)

Last year SPIE published a book I wrote called the Field Guide to Optical Lithography. No, it doesn’t contain any illustrations of the plumage of the male lithographer during courting. SPIE picked the title – it is one of a series of field guides on optical topics. Of course, they are selling the book here this week, but I was a little surprised to see their method of advertising – a pair of 8 foot tall posters each with a giant photo of my graying, smiling head. I find them a little disconcerting to look at, so I can only imagine their impact on the general lithography book-buying public. Mark Smith threatened to take a marker and write “actual size” on the posters next to my picture. Isn’t that what friends are for?

It’s always fascinating to see which sessions are hot and which are not. Last year, a session entitled “polarization and hyper-NA effects” would have been packed. This year it was empty. Not only that, but all of the papers were essentially the same (how many ways can we rewrite the Jones matrix?). The industry tends to work like that – as a mob, recognizing and working on the same problems at about the same time. We spent the year working on vector pupils, now we are done. The ‘hot’ topic this year? Double patterning, of course. Standing room only during that session.

My favorite papers so far:

On Monday in the metrology session, Tim Brunner put scattering bars too close to a feature in order to do what lithographers never want to do – make the NILS low. The result – a pattern with extreme sensitivity that can be used as a focus and exposure ‘canary’ monitor.

In the resist session on Tuesday, John Biafore explained some of the stochastic phenomena behind line edge roughness – including totally cool movies that illustrated the main effects in a way an equation never will.

Bernd Geh made sense of the Jones matrix on Tuesday in the optical lithography conference – something I thought couldn’t be done.

SPIE AL07 – Day 1 (Monday)

The first day of the Advanced Lithography Symposium began, as it always does, with the plenary session. David Williamson, possible the world’s foremost catadioptric lens designer, won the 4th Zernike Prize for Microlithography. Much deserved. And after Burn Lin, Grant Willson, and Tim Brunner, it’s good to see that someone who didn’t work for IBM is deserving of this honor.

The plenary talks began with Hans Stork, CTO of Texas Instruments, describing the challenges of scaling CMOS down to the 32 nm node. Surprisingly, though, after giving a very good description of the challenges, he failed to mention the TI strategy for addressing those challenges. Of course, that strategy became well known a month ago when TI announced that it was laying off its R&D staff and relying on foundries for manufacturing below 45 nm. There were over 1000 people in the room for that plenary talk, and one very large elephant. I thought it was important to point to the elephant.

George Gomba then gave a very nice sales pitch for the IBM lithography cabal. I have to admit that I like the new buz-phrase “computational lithography.” I found it interesting that the logo for their lithography efforts was a single tear.

Mark Melliar-Smith followed up with a sales pitch for nanoimprint lithography as a viable alternative for 32 nm half-pitch CMOS manufacturing. On one of his concluding slides I counted up about 5 – 6 orders of magnitude improvement required to make imprint work at this node. That’s a lot, but I think it is still less than the relative orders of magnitude improvement required for EUV.

The sessions began after a coffee break, and immediately there were multiple talks I wanted to be at at the same time. Welcome to SPIE. And it seems like the meeting just keep going. At 9pm I caught the tail end of a panel discussion on double pattering, “Twice the gain for twice the pain?”. It reminded me of the old story of the frog in a pot.

Throw a frog in a pot of boiling water and he will feel the pain and jump out. But put him in cool water and he is happy. Now if you slowly start heating up the water, the frog doesn’t notice the rising temperature until it is too late, and he is cooked. So my question for everyone working on 65 nm, 45 nm, and 32 nm half-pitch lithography solutions: how hot is it now?

The SPIE Advanced Lithography Symposium – Day 0

It’s that time of year again, when a large proportion of the world’s lithographers make the annual trek to San Jose to attend their biggest conference of the year. Attendance is expected to surpass 4,000 – and that’s a lot of litho engineers. I hope the area bars are well stocked with beer.

2007 promises to be a very interesting year for lithographers. Two EUV “alpha demo” tools (whatever that means) were installed last December, so I suspect we’ll learn a great deal, good or bad, about how much work is required to make EUV practical. We’ll probably also see the next hyper-NA installment in 2007 – tools with numerical apertures in the range of 1.3 to 1.35. Is this the highest we can go? And if so, is this finally the end for optical lithography? But wait, what about double patterning? I think 2007 will be the inevitable let-down year for double patterning, a depression of reality after all the hype and expectations from last year. Then, following the normal cycle of emotions, in 2008 we’ll either figure out how to make double patterning work, or give up on it. The future of advanced lithography is cloudier than I ever remember seeing it before.

And so people come to this conference looking for answers. But people come to Advanced Lithography for many reasons. TI researchers will come looking for jobs. Freescale lithographers will be looking for recommendations on where to live in New York. Intel will come to listen, but they won’t talk. And of course, the suppliers (oh, there are soooo many suppliers) will come looking for business. What am I looking for this week? As always, two things. First, community. I’ve come here to reconnect with the people I see each year at this event, many of whom I am proud to consider my friends. And second, inspiration. The collective creativity of the men and women presenting papers at the conference is absolutely astounding. Each year I come away with far more ideas of things to do than I can possible attempt in one year.

And that’s what this conference is all about – a community of scientists and engineers taking inspiration from each other. As each of us runs as fast as we possibly can towards the brick wall at the end of Moore’s Law, its good to know we’re not alone.

An Update on Grant Willson

On July 4 of last year my friend (and fellow lithographer) Grant Willson was hit by a drunk driver – a head-on collision that crushed his hip, among other injuries. Many people have asked me for an update on Grant’s recovery. It started off very slow. He didn’t heal well from the major reconstructive surgery on his hip. Grant spent a lot of time in a wheelchair, fighting pain and an infection. Finally around Thanksgiving he had hip replacement surgery. The impact was dramatic – he was like a new man almost immediately. When I saw him on New Year’s eve, he had barely a perceptible limp and was in the best of moods. Recovery will soon be complete.

What about the drunk driver who hit him? It was his third offense. He received a seven year prison sentence, and will be up for parole in five years.

History of Murphy’s Law

So who was Murphy, anyway? You know, the guy who said “Anything that can go wrong, will go wrong,” the succinct statement of the philosophy of overengineering. I’ve always wondered, but never heard anyone tell the story. Until, that is, I was perusing some back issues of the Annals of Improbable Research, and came across an article by Nick Spark, “The Fastest Man on Earth: Why everything you know about Murphy’s Law is wrong.” It’s an absolutely fascinating tale – something anyone who has ever related to Murphy’s Law, or used Murphy’s name in vain, should read.

70 Years is a Long Time

This week, my next-door neighbors, Martha and Carroll, celebrated their seventieth wedding anniversary. What can you say other than “Wow!”

They are great people – sweet, kind, caring, sharp as a tack, and not self-absorbed. And not only that, but they are interesting, too. They’ve lived in their house since 1942 and are the unofficial neighborhood historians. Since they don’t get out much, their focus is on what is happening along our street. And they’ve drawn me in to their attitude. Instead of not knowing who my neighbors are, I know them and actually care about them – kind of a throw back to an earlier, pre-television and internet blogging way of life.

They are inspirational. I want to be like them. I don’t think I’ll see my 70th wedding anniversary (I didn’t following the first rule to having a long marriage – marry young), but I have hope for seeing, and enjoying, my 50th. They are what growing old should be like.

Here’s to you, Martha and Carroll. Congratulations!

Round-off Error

Round-off errors – not the kind of thing the average consumer spends much time worrying about. As an engineer, I was always taught to avoid round-off errors. While developing numerical modeling algorithms (hey, it pays well!), I had to be very careful to make sure round-off errors didn’t unexpectedly bite me in the butt when I wasn’t looking (though sometimes they did anyway). So I was a bit surprised (and a bit disappointed) to see a creative use of round-off error in my own kitchen – a use designed to misinform the average Joe.

Or Jane. The kind of person who thinks statistics are just for sports fanatics and fantasy football freaks. I was using a can of Pam – you know, that spray-on oil for the few people left who don’t own Teflon pans. Now Pam (or any of the many similar products) has exactly two ingredient: vegetable oil and propellant. The propellant is of negligible quantity, so basically it is a can of 100% oil. So I was surprised to see on the nutritional label that a serving of Pam contains 0 calories, 0 grams of fat, and 0% of its calories from fat. So how can a product that is effectively 100% fat be, in fact, fat free?

Round-off error. It seems that the people who regulate these labels decided that it is OK to round to the nearest 1 gram. Thus, if a serving has 2.3 grams of fat, they can just say 2 grams on the label. 12.6 becomes 13. And if the amount of fat, measured in grams, is less than 0.5? Well, you round it down to zero. So if the product is 100% fat, how can the amount of fat be less than 0.5 grams? Why, just make the serving size less than 0.5 grams! By rounding, it has exactly zero of everything! One serving of Pam is a 1/3 second spray, which makes the serving size conveniently less than 0.5 grams.

One-third of a second. I tried this, but I think fast Pam sprays are a young man’s sport. I couldn’t move my finger up and down fast enough to get less than a 3/4 second of spray. Maybe there’s a technique. But anyway, you can see how, through creative rounding, the label was allowed to say 0 grams of fat. That’s bad enough, but what REALLY gets me is the claim that Pam has 0% of its calories from fat! What is zero divided by zero, anyway? According to many high school math students, and ConAgra Foods, the makers of Pam, the answer is zero. Of course, some of us were taught that math works a little differently than that (I won’t go into L’Hopital’s rule, or that you should round your answer only after you have completed all of your calculations). You don’t need a math degree to see that the correct answer, in this case, is 100%, not 0%.

So there you have it. Round-off error biting the average consumer in the butt (which, by the way, may get a little bigger if you take the nutritional label of Pam at face value). I’m glad I paid attention in math class.

Supreme Court Roundup

I have a cousin named Kevin Russell. He’s about five years younger than me, but we grew up close to each other (in lovely Kalamazoo, Michigan) and spent a lot of time playing at each others’ houses as kids. I remember one day he gave my brother and I a Time magazine, pointing to paintings of naked women is the art review section. I was probably 10 years old at the time, and thought that was the funniest thing in the world. Kevin kept asking why we were laughing, but that just made us double up and laugh even harder. That quizzical look on his face is how I will always picture him.

I moved away when I was fifteen, but have heard about what Kevin has been up to, seen him at family gatherings – the usual stuff. He did well in college, even better at law school, clerked for a Supreme Court justice, and then went to work for the Justice Department. When he couldn’t stand another day there, he started his own practice.

Yesterday, Kevin argued his first case before the Supreme Court. Wow. It was a pay discrimination case, involving the Civil Rights Act, statue of limitations, and other legalistic stuff that I’m sure is important but don’t quite understand myself. My little cousin has done well for himself, and of course his whole family is proud. But that doesn’t mean I won’t always think of him as that little five year old with the innocent question-mark-of-a-face looking at me as if I were the fool that in fact I was.

Congratulations, Kevin. Keep doing the right thing – we need people like you.

Vote today

It’s time to go to the poles and cast your vote. And be glad you can.

They don’t much teach this in our myth-building junior high history classes, but for the first 50 years of this country, only about 15% of the adult population had the right to vote (white, male property owners). Black men nominally recieved the right to vote with their emancipation during the Civil War, but they were largely denied that right until the passage of the Voting Rights Act 41 years ago. Women got the right to vote in 1920. The universal right for adults to participate in American democracy occurred in my lifetime. I don’t take it for granted.

Bellingham, WA

Last Thursday, I found myself in Bellingham, Washington. Of course, no one goes to Bellingham – I just happened to be driving from Seattle to Vancouver, British Columbia (to attend a philosophy of science conference – I know, I have strange hobbies). Besides being a little bit hungry, I had no reason to stop and wouldn’t have given the exit from the highway another thought until I was struck by a nagging familiarity with the name of the town. Bellingham. Then it occurred to me – this was the home of SPIE, the optics professional society that hosts the two largest conferences in the semiconductor lithography world (BACUS, the former home of world-class geek entertainment, and Microlithography, now dubbed Advanced Lithography so that no one will think we are doing any of that mundane kind of microlithography we used to give papers on).

Bellingham, Washington. The place we Fed-ex our extremely overdue manuscripts in the hopes that they might still be included in the proceedings. The return address on the advanced program that we get in the mail every year telling us about the few papers we will go see and the many, many papers we will miss at the massive Microlithography (sorry, Advanced Lithography) symposium. The place where we assume real people sit and talk to us on the phone when call with a question, but of course we are never sure.

SPIE Headquarters. I don’t know anybody whose has ever been there. So I decided to go. I veered off the highway at the last minute, searched and finally found the very well hidden building that was nestled in the hills and trees of this small coastal Washington town. I asked for the people I know there – June Thompson, who used to manage the BACUS conference, and Brian Thomas, who spear-headed the effort to upsize Micro into Advanced. Luckily, they were both in town. June gave me a tour of the building (it’s very nice!), then indulged one of my (mostly) harmless obsessions and took me to a brewpub for lunch (I can say with confidence – there’s good beer to be found in Bellingham). I exchanged gossip with Brian (though, quite frankly, lithography gossip is pretty boring) and lent him a sympathetic ear as he complained about the problems running SPIE’s most successful conference. All in all, a nice time.

So if you find yourself driving up interstate 5 through Washington some day with a little time on your hands, stop by and say high to the folks at SPIE. They’re nice people, and they get lonely.

Musings of a Gentleman Scientist