2026-09-19T20:19:25Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/106268 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Zhu, Wenjuan Ryu, Hojoon 2020-03-02T21:58:29Z 2020-03-02T21:58:29Z 2019-12-09 2019-12 Ferroelectricity is the material property such that we can induce spontaneous polarization, reverse it and modulate it by varying the applied electrical field on the ferroelectric material. Recently, doped hafnium oxide (HfO2) has garnered attention with its excellent scalability, reliability, and compatibility with the current CMOS process. This thesis introduces two research projects aimed at improving the electrical properties of ferroelectric-doped HfO2 for various device applications. In the first project, we demonstrate a high-performance ferroelectric aluminum (Al) doped HfO2 capacitor with Ti/Pd gate electrode. The remnant polarization reaches up to 20 µC/cm2, endurance higher than 10^8 cycles and retention over ten years at room temperature. In the second research, we demonstrate a ferroelectric tunneling junction (FTJ) based on metal/aluminum oxide/zirconium doped HfO2/silicon structure. We show that this FTJ has artificial synaptic behavior with symmetric synaptic weight change and tunable conductance. We also show spike-timing-independent plasticity (STDP) can be obtained in this device, which proves the possibility of using our FTJ as a neuromorphic computing chip. Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2020-02-28 without embargo terms The student, Hojoon Ryu, accepted the attached license on 2019-12-09 at 11:13. The student, Hojoon Ryu, submitted this Thesis for approval on 2019-12-09 at 11:37. This Thesis was approved for publication on 2019-12-09 at 13:02. DSpace SAF Submission Ingestion Package generated from Vireo submission #14757 on 2020-02-28 at 17:16:19 Made available in DSpace on 2020-03-02T21:58:29Z (GMT). No. of bitstreams: 2 RYU-THESIS-2019.pdf: 1243795 bytes, checksum: 3bf57d1eec58a35987447658b13d32ed (MD5) LICENSE.txt: 4207 bytes, checksum: 0897e1bf1220c8cd19e4ba8ed872b0e7 (MD5) Previous issue date: 2019-12-09 application/pdf http://hdl.handle.net/2142/106268 en Copyright 2019 Hojoon Ryu Ferroelectric devices Ferroelectric material Ferroelectric hafnium oxide Ferroelectric capacitor Ferroelectric tunneling junction Non-volatile memory Neuromorphic computing Al-doped HfO2 Zr-doped HfO2 Ferroelectric doped hafnium oxide and its application on electronic devices text text Electrical & Computer Eng Electrical & Computer Engr University of Illinois at Urbana-Champaign Thesis M.S.