Lithography in Prague – EUV

I missed Monday’s papers, but I’m told that there were some good ones. On Tuesday, the highlight was ASML’s status report on their progress. In short, their progress has been remarkable. They have 800 people working on EUV lithography. Their very large EUV tool production facility opened in April of this year. It is rumored that they have invested $1B in EUV. Quite literally, they have bet the company on EUV. And when they present on their status, EUV lithography has the sense of inevitability.

[Aside: Nikon is much further behind. They have one in-house development tool, and their plan is to ship the first real tool they make to customers as a high-volume manufacturing tool in 2013. I’m doubtful. It is clear that Nikon has been unwilling to bet their company on the success of EUV lithography. Can you blame them? Canon is out of the picture. They presented an EUV lens design – that’s as far as they’ve gotten.]

Does the impressive progress of ASML mean that EUV lithography is on track to be ready for manufacturing in 2013? No. The problem is that the three major potential show-stoppers (source power, mask defectivity, and resist performance) are all outside of ASML’s control. Here’s my take on the status of these three challenges.

Source Power – Cymer has become the only game in town. The other source vendors are just too far behind. And while Cymer has made good progress, there is a long way to go (both in power and reliability, two related quantities). I find it troubling that their source development plan requires 90% of the source power improvement to come in the last 10% of the project timeline. Maybe they will do it, but the risk of failure is very high.

Mask Defectivity – Progress on this front has been too slow. Worse yet, we still don’t have measurement tools that can find the smallest defects, so we don’t even know how big the problem is. This does not inspire confidence. SEMATECH’s efforts to create a new consortium to fund mask inspection tool development (about to get underway) will likely be too little too late.

Resist Performance – There has been some good progress on resist sensitivity and resolution. But line-edge roughness (LER) is still too big by a factor of 2 or 3, and it is not getting better. There is no good model for predicting LER, and the Edisonian trial-and-error approach to finding a low-LER resist is unlikely to be fruitful. Hope seems to be pinned on post-development treatments to smooth out the roughness. But I’m not convinced that such treatments are anything more than cosmetic. Low-frequency LER is what will cause problems for devices, and post-development treatments do not (and can not) smooth out these low-frequency errors. My long-held view that the ultimate limits of optical lithography will be governed by line-edge roughness remains intact.

Overall, though, the success or failure of EUV lithography, like any manufacturing technology, will be determined by costs. Source power and resist sensitivity at adequate performance will determine throughput (wafers out per hour). Mask defectivity affects yield (good wafers out per hour). Couple that with the cost of the EUV scanner and we can estimate the cost effectiveness of EUV lithography. So how much will an EUV scanner cost? In response to a question from the audience, ASML said that an EUV scanner will weigh three times as much as a 193 scanner. Assuming price is proportional to weight (a surprisingly good correlation!), that means an EUV scanner will cost three times as much as a 193 scanner (over $100M). Since the competition for EUV lithography is double patterning, that means an EUV scanner will cost more than two 193 scanners. If we are generous and assume an EUV scanner costs the same as two double-patterning-capable 193 immersion scanners, the only way for EUV to be cost effective will be if its throughput equals today’s 193 throughput – about 150 wafers/hr. That has to be the target for EUV. Will they make it?

Postscript: As the symposium ended and all the participants filed out of the room, I noticed a different meeting taking place in the conference room next door. Glancing in the open door, I could see it was very different from meetings that I am used to – it was the contestants for the Miss Prague 2009 competition. Just a reminder that there are other things going on in the world besides lithography.

Lithography in Prague

This week, SEMATECH (along with Imec and SELETE) is sponsoring back-to-back symposia on EUV lithography and extensions to immersion lithography in Prague, Czech Republic. Since I was invited to speak at the immersion symposium, and because I love Prague, I decided to attend.

I have to begin with a story of personal transformation. Five years ago I had to have extra pages sewn into my passport because every page was full of stamps. (I won’t even tell you how many millions of miles I have flown in my life – too many.) I like traveling, especially to new locations, but even for me that amount of travel was too much. But in preparing for this trip, I glanced at my passport as I was making my travel arrangements and noticed that it had been expired for nine months! That shows how much my life has changed (much for the better) since I became a gentleman scientist (and a father) four years ago. Life is good.

I’m now here in Prague, jet-lagged and listening to EUV papers (not a happy combination). I’ll report on my impressions of the EUV conference tomorrow.

Credit Report Scam

It’s hard to admit when you have been the victim of a scam. In hindsight, it’s so obvious that just a little more attention would have averted the whole thing. You feel stupid. But you also feel used. After all, the scammers have spent a lot of time perfecting their scam and finding the best ways to trick you. And when the scammer is a large corporation, they have a certain resource advantage as well.

I am the victim of a credit report scam perpetrated by the biggest credit reporting company in the U.S. – Experian. Here is how it worked.

I am aware that I am entitled to one free credit report per year, thanks to federal legislation. Of course, however, I do not have the website address memorized where I can get that free credit report (answer: www.annualcreditreport.com). So, I Googled it. While the top search result was the one I wanted, I made the mistake of clicking on the second search result since it was titled “Free Credit Report”, and that seemed logical. The website www.freecreditreport.com looks quite respectable, and lists Experian, Equifax and TransUnion along the top. There is a very prominent button on the right with large print that says “Click Here to see your Free Credit Report & Score”. There is also some fine print on the left side that explains that it is not free. But like most people, I didn’t read that. The intentional design of the website encourages this, and like most people I was in a hurry to get past the minutia and get what I wanted. After clicking on the button and getting what I thought was my free credit report, I exited the website. They asked for my credit card number, but said they wouldn’t charge me and that it was required to “set up my account”. That was a clue, I know, but I didn’t pick up on it. I also ignored some more fine print that I should have read under the label “Privacy Policy”. Three weeks later I received my credit card bill and noticed a $15.88 charge from “info.ExperianDirect.com”. (I’m lucky I happened to look closely at my bill this month – it’s not something I usually do.) This, by the way, is not a one-time fee – it is a monthly fee. A little searching online and I found their customer service number and called to tell them they made a mistake and that I never intended to join their “Triple Advantage” monthly service. I had never even heard of the “Triple Advantage” service that I had apparently joined. But, looking back at the fine print that I had missed on the website, by asking for my “free” credit report I was in fact signing up for this service – unless I called within 7 days to cancel.

It is very clear that the business model of this website is to trick people into signing up for services and fees that they are unaware of and have no intention of agreeing to. When I called the ExperianDirect customer service number to complain, they told me they were unwilling and unable to refund the $15.88 already charged to my account. Requests to speak to a supervisor resulted in me being disconnected. A scam, pure and simple. And probably perfectly legal.

The Long Run

As George Orwell so clearly demonstrated, our language is important not just because it determines how we speak, but because it greatly influences how we think. It’s not surprising, then, that advocacy speech seeks to carefully control the use and meaning of its words, while simultaneously demeaning or muddling the words chosen by the opposition. But if you think such behavior is confined to the ungentlemanly pursuit of modern politics, think again! Consider, as a harmless example, the sport of running.

I am a runner, not a jogger. It is a sport for which I train; it is not exercise. (The difference – I compete in races, even if “winning” to me is beating my personal goal for the race.) I don’t have running clothes, it is equipment (compare running 10 miles in the Texas heat in a cotton T-shirt versus a technical shirt and you’ll know what I mean). The words and their use are all meant to convey a seriousness of purpose, something more than just having fun or getting fit.

Another common phrase among runners is the “long run”. How long does a run have to be before runners consider it long? It took me a while being around runners before I finally figured out the exact definition. Here it is: A long run is either the longest run you’ve ever done, or any run that is 20+ miles long. Thus, the first time you run ten miles you can call it a long run, but not the second time. Any time you run 20 miles or more it is a long run.

I had a long run this morning. 25 miles. My longest to date.

Aside: Speaking of long runs, my next door neighbor turned 100 years old yesterday. He still lives independently with his wife (they’ve been married for over 70 years) in the house they bought in 1942. He is my hero. Congratulations, Carroll!

Day 3 – BACUS 2009

Day 3 is the last day of the conference this year. Due to significantly lower abstract submittals, the meeting was shortened by a day. After a set of fairly good papers in the morning, the afternoon was filled solely with a panel discussion (which I skipped in order to get home early).

Overall BACUS was a good conference, but it is definitely a shadow of its former self. Its not just that attendance was down (close to 600, versus something like 1000 each year during the middle of this decade), the energy level of the conference was down as well. It was worthwhile, but not exciting; fun but not one of the highlights of my year. Of course most of the malaise is due to the economy, but part is due to the state of the technology as well. EUVL is making progress, but any rational person has to be very skeptical of its eventual success. Double patterning receives too many complaints about cost, and especially mask costs (a sensitive topic at this conference), to be excited about it. Imprint will likely play important niche roles in manufacturing, but won’t save CMOS. Mapper is interesting, but may be too late to be a big player. Where does that leave us? Not having as much fun as we used to.

But moods can change quickly (like when everyone realized almost simultaneously that immersion lithography was real). We’ll see what happens this spring, where the only thing that is inevitable is a smaller Advanced Lithography conference in San Jose.

Day 2 – BACUS 2009

I began the second day with a four mile run on the beach, watching Venus and the crescent moon disappear as the sun rose behind the city of Monterey. Glorious. I ran with Charlie King, and had trouble keeping up with him. But then, he is so much younger than me.

Since I was way behind on finishing up the paper I had to give in the afternoon, I missed most of the morning talks. There were some very nice talks in the afternoon, but unfortunately mine was the only one on my favorite topic – line-edge roughness. My conclusion: mask writer-induced line-edge roughness cannot be ignored.

Best new product acronym: LAIPH – Luminescent Automated Image Processing Hub. The author pronounced it as “life” but it looks more like it should be pronounced “laugh”. It’s good to see that Luminescent is spending their money on engineering rather than marketing.

My broken record: I’m sorry to say that the lower number of papers at the conference has not resulted in a lower number of papers containing graphs with no numbers on the x and y axes. Why would someone show a graph in their presentation that contains absolutely no information? I don’t get it.

I enjoyed the dueling papers by KLA-Tencor and the German mask shop AMTC, where KLA showed that more measurement data was needed to know that a photomask was in spec, and the mask shop countered that less data was needed (their masks are just that good!). I found the KLA-Tencor paper (which used a non-KLA measurement tool, by the way) more convincing.

The day ended with the conference banquet, but with something missing. No entertainment. 2005 was the last year with true BACUS entertainment (skits and songs by industry insiders full of corny insider jokes). The demise of the entertainment is a long story – maybe I’ll tell it (from my perspective) someday. But I do miss it. If you have never seen it, or want to be reminded of it, check out these pictures from the days when I was a part of the cast.

Day 1 – BACUS 2009

It’s great to be back in Monterey! I’m at the 29th annual BACUS Photomask Technology Conference. This is its 10th year in Monterey, and unfortunately I’ve missed the last few years due to teaching commitments at UT. But I’m not teaching this fall, so I couldn’t pass on this one.

Monterey, California will always be a special place for me. I met my wife for the first time here seven years ago. And we got married in Monterey 15 months later. A beautiful town during a beautiful time of year. Oh yes, and the conference is usually a good one as well.

[Aside: BACUS is not a reference to the god of wine, despite the amount of that liquid consumed at the poster session each year. It is an antiquated acronym standing for the Bay Area Chrome Users Society – something I’ll bet that a majority of conference attendees don’t know.]

The day began with Mike Polcari, CEO of SEMATECH, giving the keynote address. He gave the standard compelling argument for collaborative research, and the standard not-so-compelling argument for EUV lithography. My favorite quote: “EUV is inevitable”. It reminds me of Mr. Smith from the movie The Matrix saying “Do you hear that? That is the sound of inevitability.” Surreal.

There was an abundance of papers coupling simulation with high resolution mask inspection images to automatically predict defect printability. I remember working on this eight years ago with Intel, back when nobody else would listen to the idea. Patience is a virtue. It could also be that every struggling OPC company with an aerial image model is desperately looking for a product that might sell.

Attendance at the conference this year is down, but not nearly as much as I would have expected. Maybe companies are anticipating the beginnings of a recovery. The mood is definitely less pessimistic (less pessimistic is the new optimistic), thinking that the worst is behind us. Let’s hope so.

Runner’s High

Now that I have started distance running, many friends have asked me if I am enjoying a “runner’s high”, that burst of endorphins that comes from a body’s response to prolonged and inexcusable abuse. I know that my experience with various types of highs is more limited than others (I admit it – I’ve lived a boring life), but I don’t think that any part of running a very long distance can be compared with getting high. But don’t get me wrong – there is pleasure associated with running. In particular, I feel really great when I stop.

That reminds me of an old joke: A man walks into a doctor’s office, raises his arm over his head, and says, “It hurts when I do this.” Doctor: “Then stop doing that.”

But I don’t think I’m confusing a lack of pain for pleasure. The feeling is much more than that. At the end of a long run, where I really wear myself out, once I get my breath back I feel totally and completely relaxed. All the stress of the day or week has escaped the muscles that are now too tired to support it. And if I’m lucky enough to be able to spend the rest of the day on the couch with a cold drink and the Sunday paper, that stressless state can last a long time. As far as I’m concerned, that’s better than any high I can think of.

Tropical Topical Lithography

Two weeks ago (has it been two weeks already?), the 2009 International Workshop on EUV Lithography began on the island of Oahu. Waikiki beach, to be exact. After two days of short courses (I taught one on Tuesday), the two-day workshop began on Wednesday.

By my estimation there were about 50 people in attendance – a very nice size for getting to know people and making connections (I did both). The workshop began with a keynote talk by Sam Sivakumar of Intel. Mostly boilerplate stuff – why EUV lithography is needed, what progress has been made, and where the gaps are. He did mention, though, that Intel’s “15 nm node”, which will have about a 30 nm half-pitch (for the SRAM) and enter high-volume manufacturing in 2013, is still ambiguous as to whether EUV or double patterning will be used. During the question and answer I pressed him on this point, and he admitted (for the first time, as far as I know) that the Intel plan of record for their “15 nm node” will be double patterning, switching “quickly” to EUVL once it is proven more cost effective.

[For the fun of it, let’s render that last statement in the ultimately concise language of corporate technospeak: The current Intel POR for 15nm HVM is DP, not EUVL.]

[Why the “scare quotes” around Intel’s “15 nm node”? With a 30 nm half-pitch, I would call this the 30 nm node. But then, I don’t have a degree in marketing.]

Samsung then gave an even more generic talk on EUV mask readiness (synopsis: not ready). Over a glass of wine later that evening, a Samsung litho engineer gave me the quick answer as to why Samsung is so interested in EUVL. After a thorough economic analysis, Samsung doesn’t believe it can make a profit producing DRAM using double patterning. Thus, without the scaling that an economically viable EUV lithography process would enable, life for the average Samsung lithographer would become (more?) hellish (meaning an unending focus on cost rather than technology). I can’t blame him for working hard to make EUVL successful.

After the keynotes, Hiroo Kinoshita of the University of Hyogo received a Lifetime Achievement Award (plaque plus a >$1000 cash-filled envelope) from the workshop organizers and EUV community. Sometimes described as the “father of EUV lithography”, Kinoshita did the first work and wrote the first paper on EUVL in the mid-1980s while at NEC. I got to know Hiroo a few years ago when he translated my Field Guide to Optical Lithography into Japanese. Thus while I’m quite biased, he’s a great guy, and I was happy to see him receive such acclaim.

The second day of the workshop began with a panel discussion on the status of EUVL R&D. I asked the question about who is doing the fundamental research needed to understand the causes of line-edge roughness (my current topic of interest, as I believe it will prove to be the fundamental limiter to optical lithography resolution). The answers were not encouraging. Later that day there were good papers by the University of Osaka in Japan and Hanyang University in Korea, but I think the answer is that not enough fundamental work on this topic is being done.

In the end, I enjoyed the workshop, and I came away as convinced as ever that Vivek Bakshi will never drive my Lotus.

It is now ten days after the workshop ended, and I am still here in Hawaii. I love the life of a gentleman scientist.

EUV Lithography in Hawaii

I’m back once again in the great state of Hawaii. Like last year, my nominal excuse is to attend the International EUV Lithography Workshop. And while I am still at work writing up my blog post on this topic (it is amazing how quickly I acclimate to island time), here is something to tide the interested reader over. Sally Adee, a journalist with IEEE Spectrum, was at the workshop and has been blogging on what she saw.

http://www.spectrum.ieee.org/blog/semiconductors/devices/tech-talk/i-believe-in-euvl-i-do-i-do

http://www.spectrum.ieee.org/blog/semiconductors/devices/tech-talk/intel-fellow-gunshy-about-euv-future

Wow. Did I really say all that?

Musings of a Gentleman Scientist