SPIE Advanced Lithography Symposium 2021 – day 2

Attending a virtual conference is obviously much different than in-person.  When it comes to Advanced Lithography, one of the biggest differences is the lack of parallel sessions.  A typical Tuesday at the San Jose Convention Center would involve dashing between sessions to catch talks, sometimes cursing that the two talks I wanted to see most were at the same time, and sometimes realizing that there are no talks I want to see for the next two hours.  There is a lot of “task switching”, where my mind alternates among the physics of shot noise, the chemistry of resist development, and the usefulness of the latest metrology tool advance.  This week on Tuesday, I binge-watched all the metrology talks (or rather, the 50% or so of them I was most interested in).  It was both fun and exhausting.

As one might expect, the highlights for me were the topics that most closely related to my work.  I watched the presentations on the latest SEM tools, though there was essentially nothing related to the physics of SEM image formation, my special interest.  There were many papers on how to employ SEM contours in metrology use cases rather than just traditional CD values, a topic that I have been seeing at this conference for 25 years.  It seems we have still not solved all the many issued required to make that happen.  Yosuke Okamoto’s talk helps explain why – contours can change significantly depending on the scan direction of the CD-SEM.

Of course, there were many papers on roughness measurement, with most of them related to machine learning in some way.  I have to admit that I am not a big fan of image denoising.  Maybe I’m just an old guy who prefers understanding the physics rather than letting a neural network make connections we can never understand.  I also think that many people working on image denoising are not carefully defining metrics of success that a metrologist would appreciate, things like accuracy and precision, repeatability and the size of the error bars around your answer.  Getting an image that looks less noisy is not success.

I liked George Orji’s talk on wavelet analysis of roughness.  Someday I’ll have to do the work to really understand wavelets, beyond the surface level I have today.  My hat’s off to George Papavieros for trying to measure LER with a SEM pixel size (in the direction perpendicular to the line edge) that is greater than the 3sigma LER.  That is not something I want to try.  I am a big fan of the stochastic process window (something that both Fractilia and ASML have been promoting lately), and there were a few ASML talks with some interesting results.  In a stochastic process window, one includes stochastics measures (such as defectivity, LCDU, or unbiased LWR) in the focus-exposure process window determination in addition to CD.  From Mary Breton’s talk I got a good sense of the nanosheet gate fabrication process and what metrology needs exist at each step.

I also watched the EUV conference keynote, a “live” event on Zoom.  Jos Benschop gave a very nice (prerecorded) talked, followed by live Q&A.  And sure enough, it was the Q&A that was the most interesting part.  I also will have a live event Wednesday afternoon (3pm Pacific Time), a tutorial and networking event.  This is a new presentation format for this conference, so we are all anxious to see how it will go.  The 35-minute prerecorded tutorial on the power spectral density will be followed by 25 minutes for Q&A and networking.

With my metrology binge-watching over, it is time to move on to the other conferences as the next day begins.

SPIE Advanced Lithography Symposium 2021 – day 1

As with the in-person version of this symposium, AL21 began Monday morning with an opening session and two of the three plenary talks.  This was a “live” event, though I think a recording of it will show up in the SPIE Digital Library soon.  The first item of business was the awarding of new SPIE Fellows in the lithography community.  Congratulations to Yi-sha Ku of ITRI in Taiwan, Anna Lio of Intel, John Robinson of KLA, and Mark Somervell of TEL for becoming fellows this year.  The Frits Zernike Microlithography Award went to Bruce Smith of RIT – congratulations for this well-deserved honor.  It is also a bit overdue, due to Bruce’s long-time service as the chair of the Zernike Award committee, which made him ineligible until he left that post.

The Nick Cobb Memorial Scholarship went to Yuka Esashi of the University of Colorado Boulder, who is working on her PhD in Physics on the topic of EUV reflectometry.  I had a chance to talk to Yuka during a virtual student networking event later that evening and I suspect she will be much sought after in the semiconductor industry when she graduates in a couple of years.

After the loss of one of the greats from our community, Bill Arnold, it was appropriate that his friend and colleague Mircea Dusa gave a nice overview of his contributions to our industry and a series of remembrances about his life.  Thank you, Mircea.  Bill will be missed.

The opening remarks ended with an overview of the changes that will come to this symposium next year.  First, the name of the symposium will change from Advanced Lithography (AL) to Advanced Lithography and Patterning to reflect the continued integration of lithography with deposition, etch, and other processes to produce complex patterns.  The biggest change will be the merging of the optical and EUV lithography conferences into the “Optical/EUV Nanolithography and Practices” conference, reflecting the emergence of EUV as a manufacturing technology.  The computational lithography pieces of the old Optical Lithography conference will now go to the renamed “DTCO and Computational Patterning” conference.  There have also been a few smaller changes to the scopes and names of the other conferences.  The result will be a symposium with six conferences next year, rather than the seven we have this year.

As Michael Mayberry of Intel began his plenary talk, I quickly realized one of the major downsides of a virtual conference.  It seems that none of my regular work meetings for the week have been cancelled.  How did that happen?  I had to leave Mike’s talk just as he was getting started.  Eventually, I believe that this plenary will be available on the SPIE Digital Library so I can finish watching it, but not yet.

I did see John Hu of NVIDIA give his plenary on trends in high performance computing.  While I enjoyed the talk in general, I have two specific complaints that can’t go unmentioned.  First, as an example of the power of GPU rendering he showed a clip of a digital supermodel walking around in a bathing suit.  This is obviously inappropriate for a technical conference, especially one in a male-dominated industry like ours.  Second, at the end of his talk, he described the goal to “create a virtual world better than real”.  Really?  First of all, I don’t think that could ever happen.  But if it ever did that only means we should stop working on creating better virtual worlds and focus on improving the real one.  Time to pick a better goal.

I also began the process of working my way through the many interesting technical talks (viewable on demand).  I’ll have more to say about what I am learning from them in a subsequent post, but let’s just say I’m a fan of 1.5X speed.

SPIE Advanced Lithography Symposium 2021 – prologue

Beginning in 2006, I have blogged each year at the SPIE Advanced Lithography Symposium, the major event of the year in the field of lithography and patterning.  Each morning of the conference I would wake up very early and write a post about my impressions from the day before.  (A complete collection of these “conference diaries” can be found here.)  I have always enjoyed the process of writing, and even more enjoyed the reactions these posts got.  Numerous people, unable to attend, would following along with my posts and capture just a small sense of what this fantastic event was all about.  Putting my thoughts into words has always been clarifying for me, with the added benefit of helping me organize the massive amount of information that was flooding over me, with the hope that some if that knowledge might stick.

This blogging tradition is just one more casualty of the crazy pandemic year.  At last year’s conference we were all talking about Covid, using hand sanitizer, and wondering whether it would actually turn into a pandemic.  I think, in hindsight, we were very lucky that the 2,000 attendees had no known transmissions during the conference.  Within two weeks of the end of AL 2020 much of the country began shutting down.

And now it is one year later.  An in-person conference is out of the question.  Instead, SPIE has created a “Digital Forum” for AL 2021.  There will be a few “live” events sprinkled throughout the week, but all of the technical talks have been prerecorded and are available for viewing at any time during the week to conference “attendees”.  The registration fee for the conference is about half the cost for attending in-person last year.  The first live event will be the conference kick-off on Monday (8am pacific time).

Of course, I will miss being there in person, seeing old friends and making new ones, talking in the hallways, drinking too much coffee in the mornings and beer in the evenings, laughing and learning, even doing a little business on the side.  I will miss seeing the audience when I give a talk.  I will miss approaching the microphone to ask a question after listening to someone else’s talk.  But given our current reality, I am looking forward to attending this week’s on-line events and binge-watching technical talks.  I’ll take advantage of the unique benefits of asynchronous viewing, slowing down or speeding up the flow of information to my needs and desires.  It won’t be perfect, but I think it will be good.  Let the Digital Forum begin!

Bill Arnold

It is with great sadness that I report the death of my friend and colleague William (Bill) Arnold. He died this morning after a long battle with cancer.

I met Bill in 1986, when he was already an important figure in the field of lithography. At AMD he blended theoretical understanding of imaging with the practical know-how of getting things done in manufacturing. He went on to become Chief Scientist at ASML before retiring a couple of years ago. He was also President of SPIE in 2013, one of his many acts of giving back to the community that he loved.

But these and many other technical achievements, numerous and significant though they were, pale in comparison to the humanity and generosity that defined Bill’s personal impact throughout his career. He was wicked smart, clear and insightful, and always willing to discuss or explain a subtle point. He was honest and straightforward, someone you could trust to be forthright even when business was on the line or competitors were in the room. He cared deeply about his work, and the lithography community he spent so many years working within. He was greatly respected as a technologist, manager, colleague, and friend.

In short, he was the kind of person I admired and strived to be like. I will miss him.

Added note to my post: Here is the SPIE “In Memoriam” post for Bill.

https://spie.org/news/william-arnold_obit

The Bacchanalians Return

In years past, the annual SPIE conference on photomask technology (referred to as BACUS by us old-timers) included an entertainment program with insider jokes and songs from industry folks (who called themselves “Bacchanalians”). The conference was all online this year, so some of the Bacchanalians made of few videos in the spirit of the BACUS entertainment. Thanks to Any Neureuther, Bryan Reese, and Tony Vacca for giving us something to smile about, and for reminding us of the long tradition of fun we had at the BACUS Entertainment.

Andy Neureuther inspires the NFL

EUV-a-Matic 2020

Masks for the Internet of Things

Where I am NOT this week

Like most people, I am at home this week. Where I am NOT is New Orleans, attending the 3-beams conference (EIPBN, the Electron, Ion, and Photon Beam Technology and Nanofabrication conference), which has been canceled this year. To see where I hope to be this time next year, this is how the conference chairs announced the venue for 2021:

Solar Panels, Year 3

Here is another annual update on my solar production and electricity consumption. In late January, 2017, I turned on my new solar panels. I have 30 panels, 320 W each, for a total capacity of 9.6 kW (LG320 NeON2 MonoX Plus panels with microedge converters). In the first year I generated 96% of the electricity I consumed (a magical year, with near perfect weather – sunny, but not too hot). The second year was not as good since my consumption went up 6% and my generation was down 10%. The result was that my panels generated 81% of my usage for the second year. The third year is off a little more. My consumption when up 1.5%, and my generation was down 5% compared to the second year. The final result is that the panels generated 76% of my usage in the third year. The weather is the biggest variable, and I need to find an authority that measures the amount of sunshine in Austin so that I can try and determine if there are any other factors than that at play.

A lithography casualty

The canceling of conferences has become an inevitable consequence of the COVID-19 pandemic.  Today the first lithography conference took a hit.  The 64th International Conference on Electron, Ion, And Photon Beam Technology and Nanofabrication (EIPBN, also known as three-beams or triple beam), scheduled for the end of May in New Orleans, has been cancelled.  I’ve enjoyed this conference many times in past years, and I look forward to attending again in the future.

COVID-19: the data

Like almost everyone else, I am now hunkering down in my house doing the “social distancing” thing. Since the announcement of the first confirmed coronavirus cases in Austin Thursday night (less than four days ago), events have been accelerating almost as fast as the virus has been spreading. My kids are on Spring break, but I doubt they will be going back to school next week. The supermarket shelves are getting bare. I work from home anyway, so that is no change for me.

Like everyone else, I am consuming the news about the spread of this disease. But as a data geek, I want more than what you find in the newspapers (yes, I’m old school – news is something you read, not something you watch). The first obvious place to go is the CDC website. Their data is perhaps the most trustworthy, but also conservative and a few days old. There is also the more accessible Worldometers site, with very up-to-date numbers that may be less reliable than the CDC (though I am not diving into that). Below are a couple of links and graphs from those sites. The bottom line: the number of cases in the US seems to be doubling every four days. That’s a 10X increase every two weeks. Exponentials – yikes. If we don’t flatten this curve, that will mean 400,000 cases in a month, and the entire country in two months. It is time for us to flatten the curve.

https://www.worldometers.info/coronavirus/country/us/

https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/world-map.html

World map showing countries with COVID-19 cases

(Countries with coronavirus cases shown in green, as of March 14.)

Musings of a Gentleman Scientist