{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/129696"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/129696","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Expanding electronics beyond silicon with wide-bandgap, 2D, and ferroelectric materials","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","abstract_has_math":false,"creators":["Lee, Hanwool"],"institution":"University of Illinois Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Zhu, Wenjuan","Lyding, Joseph W","Rakheja, Shaloo","Zhao, Yang"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-04-18","date_published":"2025-04-18","updated_at":"2026-07-22T22:25:05Z","subjects":["2D Materials","Ferroelectrics","Wide-bandgap","Electronics","Chemical vapor deposition","MoTe2","GaN","Reconfigurable"],"languages":["en","eng"],"rights":["Copyright 2025 Hanwool Lee"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/129696","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Zhu, Wenjuan","Lyding, Joseph W","Rakheja, Shaloo","Zhao, Yang"]},{"key":"dc:creator","label":"Author","values":["Lee, Hanwool"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-04-18","2025-05"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["2D Materials","Ferroelectrics","Wide-bandgap","Electronics","Chemical vapor deposition","MoTe2","GaN","Reconfigurable"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2025 Hanwool Lee"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/129696"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","The student, Hanwool Lee, accepted the attached license on 2025-04-17 at 01:00.","The student, Hanwool Lee, submitted this Dissertation for approval on 2025-04-17 at 01:08.","This Dissertation was approved for publication on 2025-04-18 at 16:08.","DSpace SAF Submission Ingestion Package generated from Vireo submission #21812 on 2025-10-19 at 19:53:17","This dissertation explores the advancement of microelectronics through novel materials, including two-dimensional (2D) materials, ferroelectric materials, and wide-bandgap semiconductors. These emerging materials enable new functionalities, improve energy efficiency, and enhance stability for various applications. Chapter 1 provides background information for this dissertation, including a brief review of 2D materials, particularly transition metal dichalcogenides (TMDCs). Ferroelectric materials and their device applications are discussed. Additionally, wide-bandgap semiconductors and their advantages are introduced, with a particular focus on gallium nitride (GaN). Chapter 2 explores non-volatile reconfigurable transistors with four-mode operation. Utilizing the strong polarization of epitaxially grown scandium aluminum nitride (ScAlN), a single device can function as an n-type, p-type, always-on, or always-off transistor. The feasibility of these transistors for logic gate applications is demonstrated. Additionally, non-volatile latch operation is presented using van der Waals materials, including ferroelectric copper indium thiophosphate (CIPS) and molybdenum ditelluride (MoTe2). Ferroelectric field-effect transistor (FeFET) with metal-ferroelectric-metal-insulator-semiconductor (MFMIS) structure enables stable memory operation. Using these FeFETs, non-volatile sequential logic operation is demonstrated through a simple latch circuit. Chapter 3 demonstrates the wafer-scale synthesis of MoTe2 using di-tert-butyl telluride ((C4H9)2Te) as the tellurium precursor, along with molybdenum hexacarbonyl (Mo(CO)6) and sputtered molybdenum (Mo) as molybdenum precursors. The successful wafer-scale growth of both 1T' and 2H phases of MoTe2 is presented, with various characterization results confirming the uniformity, phase selectivity, and high crystallinity of the synthesized material. Chapter 4 investigates GaN-based high-electron-mobility transistors (HEMTs) for high-temperature applications. Dielectric stack optimization, gate recess structures, and p-GaN/AlGaN/GaN heterostructures are explored to achieve stable operation up to 500 °C. Optimizing the dielectric stack enhances the breakdown field and device lifetime, while the gate recess and p-GaN/AlGaN/GaN heterostructure enable enhancement-mode operation with improved threshold voltage stability at high temperatures. Chapter 5 concludes this dissertation by summarizing key findings and outlining directions for future research. By integrating emerging materials with innovative design strategies, these studies advance next-generation electronic devices and facilitate their practical implementation in semiconductor technology."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Expanding electronics beyond silicon with wide-bandgap, 2D, and ferroelectric materials"]}]}],"canonical_facts":{"dc:contributor":["Zhu, Wenjuan","Lyding, Joseph W","Rakheja, Shaloo","Zhao, Yang"],"dc:creator":["Lee, Hanwool"],"dc:date":["2025-04-18","2025-05"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","The student, Hanwool Lee, accepted the attached license on 2025-04-17 at 01:00.","The student, Hanwool Lee, submitted this Dissertation for approval on 2025-04-17 at 01:08.","This Dissertation was approved for publication on 2025-04-18 at 16:08.","DSpace SAF Submission Ingestion Package generated from Vireo submission #21812 on 2025-10-19 at 19:53:17","This dissertation explores the advancement of microelectronics through novel materials, including two-dimensional (2D) materials, ferroelectric materials, and wide-bandgap semiconductors. These emerging materials enable new functionalities, improve energy efficiency, and enhance stability for various applications. Chapter 1 provides background information for this dissertation, including a brief review of 2D materials, particularly transition metal dichalcogenides (TMDCs). Ferroelectric materials and their device applications are discussed. Additionally, wide-bandgap semiconductors and their advantages are introduced, with a particular focus on gallium nitride (GaN). Chapter 2 explores non-volatile reconfigurable transistors with four-mode operation. Utilizing the strong polarization of epitaxially grown scandium aluminum nitride (ScAlN), a single device can function as an n-type, p-type, always-on, or always-off transistor. The feasibility of these transistors for logic gate applications is demonstrated. Additionally, non-volatile latch operation is presented using van der Waals materials, including ferroelectric copper indium thiophosphate (CIPS) and molybdenum ditelluride (MoTe2). Ferroelectric field-effect transistor (FeFET) with metal-ferroelectric-metal-insulator-semiconductor (MFMIS) structure enables stable memory operation. Using these FeFETs, non-volatile sequential logic operation is demonstrated through a simple latch circuit. Chapter 3 demonstrates the wafer-scale synthesis of MoTe2 using di-tert-butyl telluride ((C4H9)2Te) as the tellurium precursor, along with molybdenum hexacarbonyl (Mo(CO)6) and sputtered molybdenum (Mo) as molybdenum precursors. The successful wafer-scale growth of both 1T' and 2H phases of MoTe2 is presented, with various characterization results confirming the uniformity, phase selectivity, and high crystallinity of the synthesized material. Chapter 4 investigates GaN-based high-electron-mobility transistors (HEMTs) for high-temperature applications. Dielectric stack optimization, gate recess structures, and p-GaN/AlGaN/GaN heterostructures are explored to achieve stable operation up to 500 °C. Optimizing the dielectric stack enhances the breakdown field and device lifetime, while the gate recess and p-GaN/AlGaN/GaN heterostructure enable enhancement-mode operation with improved threshold voltage stability at high temperatures. Chapter 5 concludes this dissertation by summarizing key findings and outlining directions for future research. By integrating emerging materials with innovative design strategies, these studies advance next-generation electronic devices and facilitate their practical implementation in semiconductor technology."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/129696"],"dc:language":["en","eng"],"dc:rights":["Copyright 2025 Hanwool Lee"],"dc:subject":["2D Materials","Ferroelectrics","Wide-bandgap","Electronics","Chemical vapor deposition","MoTe2","GaN","Reconfigurable"],"dc:title":["Expanding electronics beyond silicon with wide-bandgap, 2D, and ferroelectric materials"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:05Z"}