visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2022-05-25 14:00 
일시 May. 25th (Wed), 14:00 
장소 E6 Room(#2501) 
연사 Dr. Duk-Hyun Choe(Samsung Advanced Institute of Technology) 

Physics Seminar

 

 

 

Atomic-level insights into ferroelectric switching and preferred orientation of ultrathin hafnia

 

Duk-Hyun Choe

Samsung Advanced Institute of Technology

May. 25th (Wed), 14:00, E6 Room(#2501)

 

Over the past decade there has been a resurgence of interest in ferroelectric (FE) devices in the semiconductor device community. This interest was sparked by the discovery of ferroelectricity in a simple binary oxide, hafnia. Unlike conventional FE perovskite, FE hafnia exhibits ultra-scalable ferroelectricity compatible with Si electronics, providing an unprecedented opportunity for the use of FEs in advanced memory and logic devices. Many proof-of-concept devices based on FE hafnia are indeed showing some promise. However, their practical engineering is still largely relying on trial-and-error process that lacks a clear theoretical guidance, and it remains challenging to rationally design the FE devices for targeted applications. Thus, the community is now calling for more fundamental investigations on the physics of ferroelectricity in hafnia.

In this presentation, we briefly review the status of the field and provide our new understanding on FE switching and surface stability of hafnia. We will first introduce an ultralow FE switching mechanism that can enable rapid growth of the FE domains in hafnia [1]. We also establish a new class of topological domain walls in HfO2, which can help understand complex domain structures often present in FE hafnia samples. Next, we present our systematic study of surface-functionalized FE hafnia [2]. We show that their remnant polarization (Pr) and coercive field (Ec) can strongly depend on the surface treatments, providing a possible explanation for the enhancement of Pr in ultrathin hafnia with preferred orientation [3,4]. We believe our study represents an important step towards bridging the gap between practical engineering and the first-principles simulations in the field of FE hafnia.

 

[1] D.-H. Choe et al., Mater. Today 50, 8 (2021).

[2] D.-H. Choe et al., IEDM (2021).

[3] S. S. Cheema et. al., Nature 580, 478 (2020)

[4] H. Lee, D.-H. Choe, S. Jo 36499 (2021).13,  ACS Appl. Mater. Interfaces et. al.,

 

Contact: Prof. Chan-Ho Yang (chyang@kaist.ac.kr) ,

Departmentof Physics / Center for Lattice Defectronics

 

Department of Physics, KAIST

번호 날짜 장소 제목
419 2023-12-14 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  Superconducting qubits for large-scale quantum computers file
418 2024-01-25 16:00  CAPP Seminar Room C303, Creation Hall, KAIST Munji Campus  [CAPP seminars] Detecting Gravitational Waves by Elecromagnetic Cavity
417 2022-09-21 16:00  College of Natural Science E6-2, Rm. 1323  Materials and Device Nanofabrication of Optical Metasurfaces file
416 2015-03-13 14:00  Connect Room, KI Bldg.  The 15th Innovative Workshop on Soft/Bio Materials file
415 2015-12-09 11:00  E4(KI Building), Connect room (2nd fl.)  Functional Imaging & Monitoring of Brain & Breast with Diffuse Light
414 2015-12-17 11:00  E4(KI Building), Matrix Hall (2nd fl.)  Wavefront engineering for in-vivo Deep brain imaging
413 2015-07-23 13:30  E4, B401  Enhanced ZnO based UV photonics and related applications file
412 2023-04-28 11:00  E6 #1323  Tkachenko wave: From the modern field theory viewpoint
411 2022-10-06 13:00  E6 #1323  Counting States with Global Symmetry
410 2023-05-17 14:00  E6 #1323  Optical Response in the multilayer thin films
409 2022-04-13 10:30  E6 #1323/zoom  Harnessing topology and correlations from singularities in 3d-kagome metals
408 2022-01-11 15:00  E6 #1501  Ultrafast optical studies on CDW collective modes of the Weyl-CDW (TaSe4)2I file
407 2022-01-26 13:00  E6 #1501  An Introduction to Cohomology groups file
406 2022-07-14 13:30  E6 #1501 & Zoom  Electronic structure and anomalous transport properties of topological materials by first principle calculation
405 2022-07-14 14:15  E6 #1501 & Zoom  Hund and electronic correlations in ruthenium-based systems
404 2022-07-14 15:00  E6 #1501 & Zoom  Pure two-dimensional quantum electron liquid and its phase transition
403 2022-08-01 10:00  E6 #1501 & Zoom  [Update 세미나 영상] James Webb Space Telescope & OTE Commissioning
402 2022-10-24 16:00  E6 #1501(공동강의실)  Physics Colloquim(Fall 2022) file
401 2022-01-25 15:00  E6 #1501/online  Emulating twisted double bilayer graphene with a multiorbital optical lattice file
400 2022-03-31 10:00  E6 #1501/zoom  Weiss fields for Quantum Spin Dynamics file