{"653403":{"#nid":"653403","#data":{"type":"event","title":"Ph.D. Proposal Oral Exam - Mingyo Park","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle:\u0026nbsp; \u003C\/strong\u003E\u003Cem\u003EAcoustic Resonators Based On Epitaxial AlN\/AlScN Ultra Thin Piezoelectric Films\u003C\/em\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee:\u0026nbsp; \u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Ansari, Advisor\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Cressler, Chair\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Ayazi\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract: \u003C\/strong\u003EThe objective of this proposal is to introduce several advances into the ultra-thin aluminum scandium nitride (AlScN) based acoustic resonators targeted for filtering application at ku band. We approach our design considering the limitations of filter bandwidth and super high-frequency operation by marrying the advantages of highly-crystalline thin films with the piezoelectric boost from the addition of Sc to AlN alloys. This results in single-crystalline epitaxial AlScN films directly grown on Si substrate using molecular beam epitaxy (MBE). Chapter 2 presents the first demonstration of acoustic devices fabricated using epitaxial AlScN films, showing significant improvement of keff2 up to 5.3 % for LWRs with the highest operating frequency of 10 GHz. FBAR device shows the super high-frequency operation at 18.8GHz (Ku-band). Another critical performance metric of an acoustic resonator is the Qkt2 Figure of merit (FoM), with robust structures that overcome thin-film fabrication challenges. Chapter 3 illustrates the first demonstration of thin-film ferroelectric AlScN-on-silicon composite resonators, targeting high-overtone resonance modes in the sub-6GHz band with a high FoM. An ultrahigh kt2 value of 11.7% at the 3rd-order TE resonant frequency of 2.4 GHz is reported, yielding kt2\u0026times;Qmax of 84, showing 2 improvement compared to the co-fabricated AlScN-only FBARs. Lastly, another objective of this proposal is to present a novel sensing scheme utilizing integrated, self-sustained, high-Q, resonant-based frequency comb sensors by employing an ultra-thin piezoelectric layer. Chapter 4 presents the first demonstrations of phononic (or mechanical) frequency combs based on non-degenerate parametric pumping using the duffing nonlinearity present in the flexural-mode ultrathin (\u0026lt;100 nm) piezoelectric resonators.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Acoustic Resonators Based On Epitaxial AlN\/AlScN Ultra Thin Piezoelectric Films"}],"uid":"28475","created_gmt":"2021-12-03 22:04:47","changed_gmt":"2021-12-03 22:04:47","author":"Daniela Staiculescu","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2021-12-08T10:30:00-05:00","event_time_end":"2021-12-08T12:30:00-05:00","event_time_end_last":"2021-12-08T12:30:00-05:00","gmt_time_start":"2021-12-08 15:30:00","gmt_time_end":"2021-12-08 17:30:00","gmt_time_end_last":"2021-12-08 17:30:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"434371","name":"ECE Ph.D. Proposal Oral Exams"}],"categories":[],"keywords":[{"id":"102851","name":"Phd proposal"},{"id":"1808","name":"graduate students"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}