{"id":654,"date":"2021-02-24T06:38:12","date_gmt":"2021-02-24T12:38:12","guid":{"rendered":"http:\/\/life.lithoguru.com\/?p=654"},"modified":"2021-02-24T06:38:12","modified_gmt":"2021-02-24T12:38:12","slug":"spie-advanced-lithography-symposium-2021-day-2","status":"publish","type":"post","link":"https:\/\/lithoguru.com\/life\/?p=654","title":{"rendered":"SPIE Advanced Lithography Symposium 2021 \u2013 day 2"},"content":{"rendered":"\n<p>Attending a virtual conference is obviously much different than in-person.&nbsp; When it comes to Advanced Lithography, one of the biggest differences is the lack of parallel sessions.&nbsp; 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.&nbsp; There is a lot of \u201ctask switching\u201d, where my mind alternates among the physics of shot noise, the chemistry of resist development, and the usefulness of the latest metrology tool advance.&nbsp; This week on Tuesday, I binge-watched all the metrology talks (or rather, the 50% or so of them I was most interested in).&nbsp; It was both fun and exhausting.<\/p>\n\n\n\n<p>As one might expect, the highlights for me were the topics that most closely related to my work.&nbsp; 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.&nbsp; 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.&nbsp; It seems we have still not solved all the many issued required to make that happen.&nbsp; Yosuke Okamoto\u2019s talk helps explain why \u2013 contours can change significantly depending on the scan direction of the CD-SEM.<\/p>\n\n\n\n<p>Of course, there were many papers on roughness measurement, with most of them related to machine learning in some way.&nbsp; I have to admit that I am not a big fan of image denoising.&nbsp; Maybe I\u2019m just an old guy who prefers understanding the physics rather than letting a neural network make connections we can never understand.&nbsp; 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.&nbsp; Getting an image that looks less noisy is not success.<\/p>\n\n\n\n<p>I liked George Orji\u2019s talk on wavelet analysis of roughness.&nbsp; Someday I\u2019ll have to do the work to really understand wavelets, beyond the surface level I have today.&nbsp; My hat\u2019s 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.&nbsp; That is not something I want to try.&nbsp; 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.&nbsp; 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.&nbsp; From Mary Breton\u2019s talk I got a good sense of the nanosheet gate fabrication process and what metrology needs exist at each step.<\/p>\n\n\n\n<p>I also watched the EUV conference keynote, a \u201clive\u201d event on Zoom.&nbsp; Jos Benschop gave a very nice (prerecorded) talked, followed by live Q&amp;A.&nbsp; And sure enough, it was the Q&amp;A that was the most interesting part.&nbsp; I also will have a live event Wednesday afternoon (3pm Pacific Time), a tutorial and networking event.&nbsp; This is a new presentation format for this conference, so we are all anxious to see how it will go.&nbsp; The 35-minute prerecorded tutorial on the power spectral density will be followed by 25 minutes for Q&amp;A and networking.<\/p>\n\n\n\n<p>With my metrology binge-watching over, it is time to move on to the other conferences as the next day begins.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Attending a virtual conference is obviously much different than in-person.&nbsp; When it comes to Advanced Lithography, one of the biggest differences is the lack of parallel sessions.&nbsp; 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 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-654","post","type-post","status-publish","format-standard","hentry","category-microlithography"],"_links":{"self":[{"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/posts\/654","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=654"}],"version-history":[{"count":1,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/posts\/654\/revisions"}],"predecessor-version":[{"id":655,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/posts\/654\/revisions\/655"}],"wp:attachment":[{"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=654"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=654"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=654"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}