{"637082":{"#nid":"637082","#data":{"type":"event","title":"PhD Proposal by Sarah Lombardo","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETHE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EGEORGIA INSTITUTE OF TECHNOLOGY\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EUnder the provisions of the regulations for the degree\u003C\/strong\u003E\u003Cbr \/\u003E\r\n\u003Cbr \/\u003E\r\n\u003Cstrong\u003EDOCTOR OF PHILOSOPHY\u003C\/strong\u003E\u003Cbr \/\u003E\r\n\u003Cbr \/\u003E\r\n\u003Cstrong\u003Eon Monday, July 27, 2020\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003E1:00 PM\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003Evia\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EBlueJeans Video Conferencing\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca href=\u0022https:\/\/bluejeans.com\/674108390\u0022\u003Ehttps:\/\/bluejeans.com\/674108390\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003Ewill be held the\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EDISSERTATION PROPOSAL DEFENSE\u003C\/strong\u003E\u003Cbr \/\u003E\r\n\u003Cbr \/\u003E\r\n\u003Cstrong\u003Efor\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ESarah Lombardo\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003E\u0026ldquo;In Situ Characterization of Polarization Switching in Antiferroelectric Fluorite-Structure Binary Oxide Thin Films for Logic and Memory Applications\u0026rdquo;\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Joshua Kacher, Advisor, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Asif Khan,\u0026nbsp;Advisor, ECE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Matthew McDowell, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Rampi Ramprasad, MSE\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EProf. Andrew Kummel, ChE, UCSD\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe need for novel, super-high K dielectric gate oxides has substantially increased in recent years. With the EOT in advanced nodes reaching a limit, materials innovation can enable increased dielectric constants in gate oxide stacks beyond the current limit, providing significant enhancement in logic technologies. Capacitance enhancement and super-high K dielectric gate stacks require the use of ferroelectrics (FEs) to be stabilized in an otherwise unstable state, resulting in an effective static negative capacitance.\u0026nbsp; In well-known perovskite-based ferroelectrics, a FE-DE stack results in a depolarization field changing the ferroelectric into a high energy unstable negative capacitance state, causing a tetragonal to cubic phase transition. However, the equivalent unstable state in fluorite-based FEs (i.e., HfO\u003Csub\u003E2\u003C\/sub\u003E- and ZrO\u003Csub\u003E2\u003C\/sub\u003E-based FEs) \u0026ndash; offering full scalability and CMOS compatibility \u0026ndash; is not well-known, and it is the competition between the polar orthorhombic and non-polar monoclinic and tetragonal phases that dictates the overall properties of these films. Additionally, antiferroelectricity has been reported in ZrO\u003Csub\u003E2\u003C\/sub\u003E-based thin films, making them promising candidates for high-density energy storage, neuromorphic oscillators, and nonvolatile memory applications. Antiferroelectrics exhibit interesting non-linearities in their charge-voltage characteristics (i.e. double hysteresis loops). From a microscopic perspective, antiferroelectricity is a phenomenon in which an electric field induces a first-order, structural phase transition between a non-polar, ground state and an energetically similar, polar active state.\u0026nbsp; Since the discovery of antiferroelectricity in ZrO\u003Csub\u003E2\u003C\/sub\u003E, it has been well-recognized that the electrical characteristics associated with the field-induced phase transition in these materials can solve some of the most pressing challenges in modern microelectronics (energy efficiency, sub-Boltzmann logic technologies, memory and neuromorphic applications, etc.).\u0026nbsp; While this sets the stage for post-scaling electronics, the physical origin of antiferroelectricity in HfO\u003Csub\u003E2\u003C\/sub\u003E- and ZrO\u003Csub\u003E2\u003C\/sub\u003E-based ferroelectrics has yet to be unanimously determined nor the phase transition experimentally visualized.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThere are significant gaps in our fundamental understanding of the polycrystalline nature of ALD HfO\u003Csub\u003E2\u003C\/sub\u003E\/ZrO\u003Csub\u003E2\u003C\/sub\u003E-based FE\/AFE thin films.\u0026nbsp; Since polarization correlates with crystal structure, the application of an electric field alters the microscopic features, \u003Cem\u003Ee.g.\u003C\/em\u003E grain orientation, phase, size, and sub-grain characteristics (interphase boundaries and domain walls) of these materials. This complex evolution of microstructure enables electrical characteristics such as multi-level cell capabilities for embedded non-volatile memory, analog synapses, and abrupt transitions for artificial neurons.\u0026nbsp; On the other hand, such evolution of microstructure poses significant challenges to performance including cycle-to-cycle and device-to-device variation, reliability, and endurance. The first step towards identifying structure-performance relationships in these materials is the direct imaging of the polarization switching at the atomic and mesoscopic scales with applied bias. Due to the end of dimensional scaling of transistors, materials innovation is more crucial now than ever before to the advancement of microelectronics and modern computing.\u0026nbsp; Understanding the crystallographic pathways for ferroelectricity and antiferroelectricity in HfO\u003Csub\u003E2\u003C\/sub\u003E- and ZrO\u003Csub\u003E2\u003C\/sub\u003E-based thin films will, therefore, provide significant insight into processes necessary to optimize these material properties and enhance device performance while reducing power consumption in post-scaling electronics.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"In Situ Characterization of Polarization Switching in Antiferroelectric Fluorite-Structure Binary Oxide Thin Films for Logic and Memory Applications"}],"uid":"27707","created_gmt":"2020-07-17 21:05:39","changed_gmt":"2020-07-17 21:05:39","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2020-07-27T14:00:00-04:00","event_time_end":"2020-07-27T16:00:00-04:00","event_time_end_last":"2020-07-27T16:00:00-04:00","gmt_time_start":"2020-07-27 18:00:00","gmt_time_end":"2020-07-27 20:00:00","gmt_time_end_last":"2020-07-27 20:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"102851","name":"Phd proposal"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"174045","name":"Graduate students"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}