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
497 2016-07-08 11:00  #1323(E6-2. 1st fl.)  Isostatic magnetism
496 2016-11-11 13:30  #1323(E6-2. 1st fl.)  Bandgap Engineering of Black Phosphorus
495 2016-07-07 14:00  #1323(E6-2. 1st fl.)  Let there be topological superconductors
494 2017-02-01 14:00  #1323(E6-2. 1st fl.)  Quantum electron optics using flying electrons
493 2016-11-16 16:00  #1323(E6-2. 1st fl.)  Realizing Haldane Model in Fe-based Honeycomb Ferromagnetic Insulators
492 2018-10-19 10:00  #1323, E6-2  Energy conversion processes during magnetic reconnection in a laboratory plasma file
491 2018-05-31 16:00  #1323, E6-2  Dynamic control of optical properties with gated-graphene metamaterials file
490 2018-10-04 16:00  #1323, E6-2  Engineering light absorption in an ultrathin semiconductor metafilm file
489 2019-12-05 16:00  #1323, E6-2  Subwavelenth Photonic Devices: From Single Photon Sources to Solar Cell file
488 2019-10-15 16:00  #1323, E6-2  Moiré superlattices and graphene quasicrystal file
487 2018-10-16 10:00  #1323, E6-2  Capturing protein cluster dynamics and gene expression output in live cells file
486 2019-11-05 16:00  #1323, E6-2  Study on nanomaterials by the development of ultrahigh resolution laser-photoelectron microscopy (PEEM) file
485 2018-11-01 16:00  #1323, E6-2  Direct holography from a single snapshot file
484 2019-12-18 16:00  #1323, E6-2  Road to Higher Tc Superconductivity file
483 2018-05-09 16:00  #1323, E6-2  Recent advances in thermoelectric bulk composites file
482 2018-11-21 15:00  #1323, E6-2  Engineering topological quantum physics at the atomic scale file
481 2018-10-11 16:00  #1323, E6-2  Dirac electrons in a graphene quasicrystal file
480 2019-10-25 15:00  #1323, E6-2  Physics Seminar file
479 2019-09-18 16:00  #1323, E6-2  Exploring Synthetic Quantum Matter in Superconducting Circuits file
478 2018-10-15 16:00  #1323, E6-2  Universal properties of macroscopic current-carrying systems file