{"id":37464,"date":"2019-07-18T08:31:26","date_gmt":"2019-07-18T06:31:26","guid":{"rendered":"https:\/\/www.iemn.fr\/?p=37464"},"modified":"2019-07-18T11:17:43","modified_gmt":"2019-07-18T09:17:43","slug":"anisotropie-de-la-conductivite-thermique-artificiellement-induite-dans-des-membranes-phononiques-en-silicium","status":"publish","type":"post","link":"https:\/\/www.iemn.fr\/en\/these\/anisotropie-de-la-conductivite-thermique-artificiellement-induite-dans-des-membranes-phononiques-en-silicium.html","title":{"rendered":"Anisotropie de la conductivit\u00e9 thermique artificiellement induite dans des membranes phononiques en silicium"},"content":{"rendered":"<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-jp1x88-8e081e272bd900bf532543c6e6784648\">\n.flex_column.av-jp1x88-8e081e272bd900bf532543c6e6784648{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-jp1x88-8e081e272bd900bf532543c6e6784648 av_one_full  avia-builder-el-0  avia-builder-el-no-sibling  first flex_column_div av-zero-column-padding'     ><section  class='av_textblock_section av-jy8aewqk-c3e06da3fbfc42652c73a2cad1a16d18'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><blockquote>\n<h4><strong><a href=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2018\/03\/ico_these2.fw_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-14684 alignleft\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2018\/03\/ico_these2.fw_-80x80.png\" alt=\"\" width=\"80\" height=\"80\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2018\/03\/ico_these2.fw_-80x80.png 80w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2018\/03\/ico_these2.fw_-36x36.png 36w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2018\/03\/ico_these2.fw_-180x180.png 180w\" sizes=\"auto, (max-width: 80px) 100vw, 80px\" \/><\/a>Stanislav DIDENKO<br \/>\n<\/strong><\/h4>\n<p>Thesis defence<br \/>\n17\/06\/2019<br \/>\nIEMN Amphitheatre<\/p>\n<\/blockquote>\n<h4><strong><br \/>\nSummary:<\/strong><\/h4>\n<p>Ce travail de th\u00e8se est consacr\u00e9 au d\u00e9veloppement de m\u00e9canismes pratiques pour le guidage de chaleur dans des nanostructures de silicium de faible dimension. Les applications vont du domaine de la gestion thermique des circuits int\u00e9gr\u00e9s aux technologies et mat\u00e9riaux thermo\u00e9lectriques \u00e9mergents \u00e0 base de Si, dans lesquels le guidage thermique de la chaleur peut jouer un r\u00f4le important.<\/p>\n<p>Une s\u00e9rie de plates-formes de caract\u00e9risation thermique de taille microm\u00e9trique a \u00e9t\u00e9 con\u00e7ue et fabriqu\u00e9e. L\u2019objectif est d\u2019\u00e9tudier exp\u00e9rimentalement la faisabilit\u00e9 d\u2019une anisotropie de conductivit\u00e9 thermique (k) dans le plan, induite artificiellement, des membranes nanostructur\u00e9es en Si. L\u2019exp\u00e9rience repose sur la variation de l\u2019angle du flux de chaleur (0 \u00b0, 30 \u00b0, 45 \u00b0, 60 \u00b0, 90 \u00b0) par rapport aux r\u00e9seaux de motifs. En combinant la thermom\u00e9trie Raman, la mod\u00e9lisation optique (Rigorous Coupled Wave Analysis) et la mod\u00e9lisation par \u00e9l\u00e9ments finis (FEM), il a \u00e9t\u00e9 possible de mesurer le gradient thermique, la conductance de la membrane et de d\u00e9terminer les conductivit\u00e9s thermiques effectives. Le caract\u00e8re isotrope \/ anisotrope du flux de chaleur est clairement d\u00e9montr\u00e9. Les motifs sont caract\u00e9ris\u00e9s par le rapport des pas de r\u00e9p\u00e9titions du r\u00e9seau suivant les deux directions principales (r) avec les valeurs: [1, 1.2, 1.6, 2, 2.5]. Le rapport d\u2019anisotropie des conductivit\u00e9s thermiques est mesur\u00e9 \u00e0 2,2 (pour r = 2,5) et 1,9 (pour r = 2). En outre, une r\u00e9duction d\u2019un facteur 25 de la conductivit\u00e9 thermique, par rapport \u00e0 la valeur du mat\u00e9riau massif a \u00e9t\u00e9 observ\u00e9e pour le motif r = 2,5: k_yy = 6 \u00b1 0,6 W\/(mK). Cette exp\u00e9rience confirme la possibilit\u00e9 d\u2019induire artificiellement une anisotropie \u00e9lev\u00e9e de k; dans des membranes en silicium. L\u2019origine et les applications possibles des effets thermiques observ\u00e9s sont discut\u00e9es. Enfin, un mod\u00e8le FEM param\u00e9tr\u00e9 con\u00e7u \u00e0 dessein a d\u00e9montr\u00e9 la mise en \u0153uvre possible des effets anisotropes induits dans le domaine de la gestion thermique des circuits int\u00e9gr\u00e9s.<\/p>\n<h4><strong>Abstract:<\/strong><\/h4>\n<p>This thesis work is devoted to the development of practical mechanisms for the heat guiding in silicon low-dimensional nanostructures. The motivation comes from both the field of IC thermal management and emerging technology of Si-based thermoelectric devices, where directional heat guiding can play a an important role.<br \/>\nA series of micrometre-sized thermal characterization platforms was designed and fabricated. The objective is to study experimentally the feasibility of artificially-induced in-plane anisotropy of effective thermal conductivity (k); in Si patterned membranes. The design of experiment that relies on varying the angle of heat flow (0\u00b0, 30\u00b0, 45\u00b0, 60\u00b0, 90\u00b0) with respect to patterns\u2019 lattices is used. By the combined use of micro Raman Thermometry, Rigorous Coupled Wave Analysis (RCWA) and Finite Element Modeling (FEM) it was possible to measure the thermal gradient, membrane conductance and determine effective thermal conductivities. The isotropic\/anisotropic character of the heat flow is clearly demonstrated. The patterns are characterized by the lattice pitch ratio (r) with the values: [1, 1.2, 1.6, 2, 2.5]. The ratios of the principal k values were found be up 2.2 (for r=2.5) and 1.9 (for r=2). Besides, 25-fold reduction of the thermal conductivity, as compared to the bulk value, was observed for r=2.5 pattern: k_yy= 6\u00b10.6W\/(mK). This experiment confirms the possibility to induce artificially high anisotropy of k; in Si PhMs almost not changing the filling fraction and the diameter of lattice nanoholes. The causes of origins and possible applications of the observed thermal effects are discussed. Finally, purposefully designed parametrized FEM model demonstrated the possible implementation of the induced anisotropic effects in the area of IC thermal-management.<\/p>\n<h4><strong>JURY :<\/strong><\/h4>\n<p>\u2013 Emmanuel\u00a0DUBOIS, Universit\u00e9 de Lille, Directeur de th\u00e8se<\/p>\n<p>\u2013 S\u00e9bastian VOLZ, The University of Tokyo, Rapporteur<\/p>\n<p>\u2013 S\u00e9verine GOMES, CETHIL (UMR 5008), Lyon, Examinateur<\/p>\n<p>\u2013 Jean-Fran\u00e7ois ROBILLARD, Universit\u00e9 de Lille, Examinateur<\/p>\n<p>\u2013 Thomas SKOTNICKI, CEZAMAT, Varshava, CoDirecteur de th\u00e8se<\/p>\n<p>\u2013 Nicolas HORNY, Universit\u00e9 de Reims Champagne-Ardenne, Rapporteur<\/p>\n<\/div><\/section><\/div>","protected":false},"excerpt":{"rendered":"","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[199],"tags":[],"class_list":["post-37464","post","type-post","status-publish","format-standard","hentry","category-these"],"_links":{"self":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/37464","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/comments?post=37464"}],"version-history":[{"count":0,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/37464\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media?parent=37464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/categories?post=37464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/tags?post=37464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}