{"id":696,"date":"2023-03-03T10:07:01","date_gmt":"2023-03-03T16:07:01","guid":{"rendered":"https:\/\/lithoguru.com\/life\/?p=696"},"modified":"2023-03-03T10:07:01","modified_gmt":"2023-03-03T16:07:01","slug":"spie-advanced-lithography-and-patterning-symposium-2023-day-4","status":"publish","type":"post","link":"https:\/\/lithoguru.com\/life\/?p=696","title":{"rendered":"<strong>SPIE Advanced Lithography and Patterning Symposium 2023 \u2013 day 4<\/strong>"},"content":{"rendered":"\n<p>I began the last day of the conference at the EUV talks.&nbsp; Jo Finders of ASML described how non-idealities of the scanner can effect single-layer edge placement errors (a combination of CD errors, both global and local, and local pattern placement errors).&nbsp; This was the first time I had seen a numerical breakdown of mechanisms of \u201cNILS loss\u201d, the reduction of the Normalized Image Log-Slope from its theoretical value caused by mask topography, aberrations, flare, focus variation across the slit, etc.&nbsp; The NILS loss totaled to 15%, and Jo described various approaches to get some of that back.<\/p>\n\n\n\n<p>Suk-Koo Hong of Samsung provided \u201cspeculations\u201d on why pushing k1 below 0.4 in EUV is problematic (specifically, for printing contact holes).\u00a0 The reason is stochastics, and there seems to be a scaling with pitch and CD that is worse than the famous z-factor predicts:\u00a0 z-factor = feature size^3 * LCDU^2 * Dose-to-size.\u00a0 Plotting LCDU (local CD uniformity) versus dose produces higher than expected LCDU at the lowest doses and seems to be following a different iso-z-factor limit.\u00a0 The specifics of CD and pitch and anything else that made up the data points in his graphs, however, were not revealed.\u00a0 Still, it was an interesting way to look at the problem, one still without a solution.<\/p>\n\n\n\n<p>As an aside, Samsung gave many papers this week, and some of those papers were some of the best in the conference.\u00a0 Case in point: Hyungju Ryu presented work by Sangjim Kim (who couldn\u2019t make it here) on process control for EUV metal oxide resists (MOR, read Inpria).\u00a0 The two MOR challenges are CD variation due to sensitivity to humidity, and poor etch resistance.\u00a0 Apparently, these problems are well known to the users of Inpria resists, but they weren\u2019t being discussed publicly until now.\u00a0 For example, CD was shown to vary by 2 \u2013 8% depending on the post-coating delay.\u00a0 Samsung showed, however, that careful optimization of every resist processing step reduced the CD variation to 35% of its original value.\u00a0 Etch resistance of the MOR was not as good as expected since partially exposed resist does not have a well-connected network of core-to-core bonds necessary for best etch resistance.\u00a0 Samsung\u2019s solution was a UV flood exposure.\u00a0 They said that more work was required to make the MOR ready for high volume manufacturing, but these were good steps in that direction.<\/p>\n\n\n\n<p>On a completely different topic, Etienne Poortere of ASML showed how a carefully designed test mask coupled with voltage contrast metrology could be used to establish design rules for via connections to metal 1 in a dual damascene process of 28 nm pitch.&nbsp; The technique made evaluation of a matrix of tip-to-tip spacings and M1 via overlap rules quite easy.<\/p>\n\n\n\n<p>Back in the SEM world, Ofer Adan gave a good marketing talk on Applied Materials\u2019 new cold field emission (CFE) electron source for their inspection SEMs (and maybe for the CD SEM?&nbsp; It wasn\u2019t clear.).&nbsp; I\u2019m convinced this new CFE source is better, but I don\u2019t know why.<\/p>\n\n\n\n<p>As is usually the case, by Thursday afternoon my brain had reached its absorption limit.&nbsp; I continued going to talks, but my notes became brief as my attention strayed.&nbsp; Summing up, this week lived up to my expectations \u2013 it was the Advanced Lithography and Patterning conference back to its full glory.&nbsp; There were many solid talks \u2013 nothing earth shattering (but there rarely is), just good incremental progress towards the harder to reach goal of keeping Moore\u2019s Law alive.&nbsp; It\u2019s a shame that the memory sector downturn kept many Micron and SK Hynix lithographers away, and that Intel\u2019s troubles kept their attendance to a minimum.&nbsp; It was gratifying to see so many good papers from Samsung, and decent attendance from TSMC.&nbsp; I go away looking forward to next year.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I began the last day of the conference at the EUV talks.&nbsp; Jo Finders of ASML described how non-idealities of the scanner can effect single-layer edge placement errors (a combination of CD errors, both global and local, and local pattern placement errors).&nbsp; This was the first time I had seen a numerical breakdown of mechanisms [&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":[4,6],"class_list":["post-696","post","type-post","status-publish","format-standard","hentry","category-microlithography","tag-mircrolithography","tag-spie"],"_links":{"self":[{"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/posts\/696","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=696"}],"version-history":[{"count":1,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/posts\/696\/revisions"}],"predecessor-version":[{"id":697,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=\/wp\/v2\/posts\/696\/revisions\/697"}],"wp:attachment":[{"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lithoguru.com\/life\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}