{"id":3581,"date":"2011-07-08T16:10:01","date_gmt":"2011-07-08T16:10:01","guid":{"rendered":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/?p=3581"},"modified":"2011-07-19T20:44:36","modified_gmt":"2011-07-19T20:44:36","slug":"templated-solid-state-dewetting-for-pattern-formation-2","status":"publish","type":"post","link":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/templated-solid-state-dewetting-for-pattern-formation-2\/","title":{"rendered":"Templated Solid-State Dewetting for Pattern Formation"},"content":{"rendered":"<div class=\"pf-content\"><p>Vapor deposited thin films are rarely stable, so that when they are heated to temperatures at which atomic diffusivities are sufficiently high, they will dewet to form isolated islands. This liquid-like process, driven by surface energy minimization, can occur well below the film\u2019s melting temperature, so that structure evolution occurs via surface self-diffusion on the solid film.\u00a0 Film dewetting (sometimes called agglomeration) has long been a problem in the processing of micro-systems.\u00a0 Dewetting of silicides, metal films, and even silicon-on-insulator films has been a concern that required careful process control to avoid.\u00a0 At the same time, dewetting has also come to be appreciated as a means of producing catalysts for nanowire and nanotube growth and, increasingly, arrays of more complex structures.<\/p>\n<p>In the past, we have studied dewetting of polycrystalline to understand the conditions required to avoid dewetting, as well as to develop techniques for control of dewetting to give ordered arrays of catalysts.\u00a0 In recent work, we have studied dewetting of single crystal films, using epitaxial Ni films on MgO as a model system.\u00a0 We found that pre-patterning of the films can be used to reproducibly guide the formation of complex structures.\u00a0 Pattern formation is strongly affected by the size of the patterning relative to the film thickness, and by crystalline anisotropy of the surface energy.\u00a0 Shape evolution is governed by a specific set of fundamental processes that include formation and pinch-off of rims to form wires<sup> [<a href=\"#footnote_0_3581\" id=\"identifier_0_3581\" class=\"footnote-link footnote-identifier-link\" title=\"J. Ye and C. V. Thompson, &ldquo;Regular pattern formation through the retraction and pinch-off of edges during solid-state dewetting of patterned single crystal films,&rdquo; Physics Review, vol. B82, p. 193408, 2010.\">1<\/a>] <\/sup>, corner and edge instabilities<sup> [<a href=\"#footnote_1_3581\" id=\"identifier_1_3581\" class=\"footnote-link footnote-identifier-link\" title=\"J. Ye and C. V. Thompson, &ldquo;Mechanisms of complex morphological evolution during solid-state dewetting of single-crystal nickel thin films,&rdquo; Appl. Phys. Letts., vol. 97, p. 071904, 2010.\">2<\/a>] <\/sup>, edge faceting<sup> [<a href=\"#footnote_2_3581\" id=\"identifier_2_3581\" class=\"footnote-link footnote-identifier-link\" title=\"J. Ye and C. V. Thompson, &ldquo;Anisotropic edge retraction and hole growth during solid-state dewetting of single crystal nickel thin films,&rdquo; Acta Materialia, vol. 59, p. 582, 2011.\">3<\/a>] <\/sup>, and Rayleigh-like instabilities to form islands from lines<sup> [<a href=\"#footnote_3_3581\" id=\"identifier_3_3581\" class=\"footnote-link footnote-identifier-link\" title=\"J. Ye and C. V. Thompson, &ldquo;Templated solid-state dewetting to controllably produce complex patterns,&rdquo; Advanced Materials, vol. 23, p. 1567, 2011.\">4<\/a>] <\/sup>.\u00a0 Relatively simple pre-patterning can be used to reproducibly form patterns with more complex shapes and smaller feature sizes.<\/p>\n\n\t\t<style type=\"text\/css\">\n\t\t\t#gallery-1 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 50%;\n\t\t\t}\n\t\t\t#gallery-1 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-1' class='gallery galleryid-3581 gallery-columns-2 gallery-size-medium'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon portrait'>\n\t\t\t\t<a href='https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-01.jpg' rel=\"lightbox[3581]\"><img width=\"284\" height=\"300\" src=\"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-01-284x300.jpg\" class=\"attachment-medium size-medium\" alt=\"Figure 1\" loading=\"lazy\" aria-describedby=\"gallery-1-3582\" srcset=\"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-01-284x300.jpg 284w, https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-01.jpg 400w\" sizes=\"(max-width: 284px) 100vw, 284px\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-1-3582'>\n\t\t\t\tFigure 1: Dewetting of square patches patterned from a Ni(110) film. For the first row, the initial pattern edges (indicate by the dashed lines) lay along [100] (vertical) and [1-10] (horizontal) in-plane directions.  In the second and third row, the edges lay along [111] directions. Scale bars indicate 10 \u00b5m. (Note that the initial patch size was smaller for the third row than for the second row.)\n\t\t\t\t<\/dd><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-02.jpg' rel=\"lightbox[3581]\"><img width=\"300\" height=\"289\" src=\"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-02-300x289.jpg\" class=\"attachment-medium size-medium\" alt=\"Figure 2\" loading=\"lazy\" aria-describedby=\"gallery-1-3583\" srcset=\"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-02-300x289.jpg 300w, https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-content\/blogs.dir\/10\/files\/2011\/07\/Kim_Solidstatedewetting-02.jpg 438w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a>\n\t\t\t<\/dt>\n\t\t\t\t<dd class='wp-caption-text gallery-caption' id='gallery-1-3583'>\n\t\t\t\tFigure 2: Dewetting of cross patches with pre-patterned internal circular holes patterned from a Ni(110) film. Dashed lines indicate the initial pattern. Scale bars indicate 10 \u00b5m.\n\t\t\t\t<\/dd><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<\/div><ol class=\"footnotes\"><li id=\"footnote_0_3581\" class=\"footnote\">J. Ye and C. V. Thompson, \u201cRegular pattern formation through the retraction and pinch-off of edges during solid-state dewetting of patterned single crystal films,\u201d <em>Physics Review,<\/em><strong> <\/strong>vol.<strong> <\/strong>B82, p. 193408, 2010. [<a href=\"#identifier_0_3581\" class=\"footnote-link footnote-back-link\">&#8617;<\/a>]<\/li><li id=\"footnote_1_3581\" class=\"footnote\">J. Ye and C. V. Thompson, \u201cMechanisms of complex morphological evolution during solid-state dewetting of single-crystal nickel thin films,\u201d <em>Appl. Phys. Letts<\/em>., vol. 97, p. 071904, 2010. [<a href=\"#identifier_1_3581\" class=\"footnote-link footnote-back-link\">&#8617;<\/a>]<\/li><li id=\"footnote_2_3581\" class=\"footnote\">J. Ye and C. V. Thompson, \u201cAnisotropic edge retraction and hole growth during solid-state dewetting of single crystal nickel thin films,\u201d <em>Acta Materialia,<\/em> vol. 59, p. 582, 2011. [<a href=\"#identifier_2_3581\" class=\"footnote-link footnote-back-link\">&#8617;<\/a>]<\/li><li id=\"footnote_3_3581\" class=\"footnote\">J. Ye and C. V. Thompson, \u201cTemplated solid-state dewetting to controllably produce complex patterns,\u201d <em>Advanced Materials,<\/em> vol. 23, p. 1567, 2011. [<a href=\"#identifier_3_3581\" class=\"footnote-link footnote-back-link\">&#8617;<\/a>]<\/li><\/ol>","protected":false},"excerpt":{"rendered":"<p>Vapor deposited thin films are rarely stable, so that when they are heated to temperatures at which atomic diffusivities are&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[5528,6083],"tags":[69],"_links":{"self":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts\/3581"}],"collection":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/comments?post=3581"}],"version-history":[{"count":3,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts\/3581\/revisions"}],"predecessor-version":[{"id":4172,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/posts\/3581\/revisions\/4172"}],"wp:attachment":[{"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/media?parent=3581"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/categories?post=3581"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mtlsites.mit.edu\/annual_reports\/2011\/wp-json\/wp\/v2\/tags?post=3581"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}