SPIE – Day 1

The SPIE Advanced Lithography Symposium always begins on Monday, unless you take (or teach) a short course the day before. Only 12 courses are being taught this year, a low not seen this millennium and indicative of austere times. Still, short course attendance was up a tiny bit, and my course was full, and as always was fun to teach. I had two young engineers from Egypt in my class, and when I congratulated them on recent events in their country, the class broke into spontaneous applause in solidarity. Nice.

There are 567 papers at the conference (and in this year’s most inane statistic, 8.5% of the authors are from Texas). Attendance at the symposium is up about 10% – a good sign, though we are still way down from our peak of 2007. I suspect those heady days will not return. But the crowd is energetic, with passions, excitement and doubts about the future of lithography alternating in about equal measure.

Monday began with awards at the plenary session. It was great to see Andy Neureuther, (mostly) retired from UC Berkeley, receive the 8th Frits Zernike award. Andy’s first paper on lithography simulation was published 40 years ago, and his body of work has been a tremendous influence on me. Four new SPIE Fellows were inducted, and I was ecstatic to see my dear friend John Petersen so honored. Bob Socha of ASML become our youngest Fellow, though thankfully he is not as young as he looks.

The two plenary talks were two sides on one coin: why more Moore’s Law is more goodness. Luc Van den Hove, the President of CEO of Imec (and someone who once gave papers at this conference – a long time ago) said more Moore would make the world a better place. I’m not sure that his example of an electronic nose for smart phones convinced me. He also didn’t convince me when he said, discussing lithography alternatives, that “EUV lithography is the more developed, more mature technology.” But then, Imec has always been a cheerleader for their Dutch neighbors.

Shang-Yi Chiang of TSMC gave a more grounded plenary talk, saying more Moore meant more money. He is hoping for EUV lithography at the 14-nm node, but only if the throughput is >100 wafers per hour. He reiterated what we all already know, that lithography cost is the biggest challenge to extending Moore’s law through the rest of this decade. Which is why no one likes double patterning (though everyone is doing it). While Chiang struck an agnostic tone about various lithography alternatives, he put on his cheerleader hat to talk about 450-mm wafers. He is hoping to find various governments that will put up $750M over the next three years to induce tool makers to develop 450-mm tools. Even if we find the money (and good luck with that), I think this is a lost cause. How about this for a fanciful thought: imagine a 450-mm production EUV lithography tool.

By 10:30 am the technical talks began. Patrick Naulleau discussed the challenges of EUV resists and lamented that EUV resist resolution has been stuck at 20-nm lines and spaces for the last three years. This doesn’t surprise me, since we haven’t had a new EUV exposure tool in the last three years. We shouldn’t expect a magic resist to make up for a lack of tools. Jim Thackeray said there is still room to improve EUV resists (as of course is true). At 193-nm we worked hard to make our resist more transparent, but at EUV we are trying to make them more absorbing (every photon is precious, and unabsorbed photons are wasted photons). Teflon has the kind of absorption we need, so know we just need to figure out how to make our resists more Teflon-like. Roel Gronheid of Imec gave a great talk, showing what I thought was a very convincing demonstration that secondary electron blur in EUV resists was less than 4 nm. One less thing to worry about, since none of us know how to reduce this source of resist blur.