{"id":3356,"date":"2026-02-23T10:09:42","date_gmt":"2026-02-23T09:09:42","guid":{"rendered":"https:\/\/www-preprod.cnrs-imn.fr\/projects-collaborations\/academic-projects\/anr-psicryo\/"},"modified":"2026-04-01T12:00:06","modified_gmt":"2026-04-01T10:00:06","slug":"anr-psicryo","status":"publish","type":"page","link":"https:\/\/www.cnrs-imn.fr\/en\/projects-collaborations\/academic-projects\/anr-psicryo\/","title":{"rendered":"ANR PSICryo"},"content":{"rendered":"

ANR project<\/p>\n<\/div>

Fundamental study of plasma-surface interactions in advanced cryogenic etching processes<\/h2><\/div>
<\/div><\/div>

Dates:<\/strong>
\nOctober 2020 – September 2024<\/p>\n

Project coordinator:<\/strong>
\nLaboratoire des technologies de la micro\u00e9lectronique (LTM Grenoble)<\/p>\n

Partner laboratories :<\/strong><\/p>\n

    \n
  • IMN<\/li>\n
  • Research Group on the Energetics of Ionized Media (GREMI Orl\u00e9ans)<\/li>\n<\/ul>\n

    IMN staff involved:<\/strong>
    \nChristophe CARDINAUD, Aur\u00e9lie GIRARD<\/p>\n<\/div>

    <\/div><\/div>

    Initially used for deep silicon etching, cryogenic etching involves etching materials at very low temperatures, with the substrate cooled to around -100\u00b0 or -150\u00b0C using liquid nitrogen. Cryogenic processes have the advantage of low reactor contamination (passivation layers form only on cold surfaces), which prevents process drift and makes them suitable for new applications (3D IC\/Si integration, MEMS) requiring smooth sidewalls and damage-free etching. As a result, scientific and technological interest in cryo-etching continues to grow. Cryo-etching of conventional materials (Si, Ge, GaN, InP) or emerging 2D materials (graphene, MoS2), oxide\/nitride compounds, and porous SiOCH (low-K) materials is being considered. Damage-free or highly selective cryo-etching processes in aggressive dimensions (below 20 nm) are also being investigated. However, many questions remain as to the fundamental mechanisms involved in cryo-etching. The formation, stoichiometry or thermal desorption of passivation layers are not fully understood. And little is known about the differences between elementary surface reactions at ambient and cryogenic temperatures. <\/p>\n

    In this context, the PSICryo project aims to study the fundamental mechanisms of plasma-surface interaction at cryogenic temperature, and to develop innovative cryo-etching processes (cryo-ALE) on various materials for advanced microelectronic applications.<\/p>\n

    Three main objectives are targeted. The first is to provide an overview of the reactions involved (physisorption, chemisorption) on an atomic scale. The second is to obtain quantitative information (nature, energy, flux, residence time) on the plasma species (ions, radicals, stable molecules) impacting the substrate, and to compare their surface reaction probabilities (bonding, sputtering, by-product formation, etc.) at room and cryogenic temperatures. The third is to correlate plasma conditions and surface temperature with the modification of exposed materials. <\/p>\n

    In terms of strategy, the project will first focus on Si cryo-etching in SF6\/O2 plasmas (with or without a SiF4\/O2 step), a textbook case but an essential step towards a better understanding of fundamental interaction mechanisms at low temperatures. The cryo-ALE of SiO2 (with C4F8 gas adsorption \/ Ar plasma sequences) will then be studied, in order to understand the nature of (ion-induced) reactions between physisorbed C4F8 molecules and SiO2 in this innovative process. Finally, the cryo-ALE concept will be extended and tested on new materials (TiN, TiO2) of interest for the nanostructuring of gate oxides (high-K) and contacts. To achieve these objectives, we will develop atomistic simulations (molecular dynamics), coupled with advanced in situ diagnostics of the gas phase (probes, UV-VUV absorption spectroscopy, mass spectrometry, ellipsometry) and exposed materials (in situ XPS analysis). Thanks to this expertise, we will provide new and fundamental knowledge on a known but only partially explored technology (Si cryo-etching in fluorinated chemistries), and then address the emerging cryo-ALE of new materials for innovative applications in 3D microelectronics. In this way, the project should have an impact on both etching technologies and information and communication sciences in general.<\/p>\n<\/div><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":3,"featured_media":0,"parent":3331,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"100-width.php","meta":{"footnotes":""},"class_list":["post-3356","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/pages\/3356","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/comments?post=3356"}],"version-history":[{"count":2,"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/pages\/3356\/revisions"}],"predecessor-version":[{"id":3369,"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/pages\/3356\/revisions\/3369"}],"up":[{"embeddable":true,"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/pages\/3331"}],"wp:attachment":[{"href":"https:\/\/www.cnrs-imn.fr\/en\/wp-json\/wp\/v2\/media?parent=3356"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}