Integration of ferroelectric BaTiO3 with Ge: The role of a SrTiO3 buffer layer investigated using aberration-corrected STEM

Hsinwei Wu, Sirong Lu, Toshihiro Aoki, Patrick Ponath, John G. Ekerdt, Alexander A. Demkov, Martha McCartney, David Smith

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The integration of semiconductors with ferroelectrics having a controlled polarization direction is an ongoing and challenging topic of research. In this work, BaTiO3 (BTO)/SrTiO3 (STO) heterostructures were grown by molecular beam epitaxy either directly with STO substrates or by using 2-nm-thick STO buffer layers on Ge(001) substrates. Sharp, chemically abrupt interfaces and c-axis-oriented BTO films for both types of heterostructures were observed using aberration-corrected scanning transmission electron microscopy and elemental mapping. Anti-phase boundaries as well as 〈100〉 misfit dislocations were present in the BTO/STO samples, with the offsets of the dislocation cores varying by distances between 1 and 5 nm away from the BTO/STO interface. Conversely, misfit dislocations were not observed in the BTO/STO/Ge structure although vertical anti-phase boundaries were still common. Overall, the results emphasize the benefits of identifying a suitable buffer layer to ensure the growth of a high quality material having the desired out-of-plane ferroelectric polarization.

Original languageEnglish (US)
Article number252901
JournalApplied Physics Letters
Volume110
Issue number25
DOIs
StatePublished - Jun 19 2017

Fingerprint

aberration
antiphase boundaries
buffers
polarization
molecular beam epitaxy
transmission electron microscopy
scanning electron microscopy

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Integration of ferroelectric BaTiO3 with Ge : The role of a SrTiO3 buffer layer investigated using aberration-corrected STEM. / Wu, Hsinwei; Lu, Sirong; Aoki, Toshihiro; Ponath, Patrick; Ekerdt, John G.; Demkov, Alexander A.; McCartney, Martha; Smith, David.

In: Applied Physics Letters, Vol. 110, No. 25, 252901, 19.06.2017.

Research output: Contribution to journalArticle

Wu, Hsinwei ; Lu, Sirong ; Aoki, Toshihiro ; Ponath, Patrick ; Ekerdt, John G. ; Demkov, Alexander A. ; McCartney, Martha ; Smith, David. / Integration of ferroelectric BaTiO3 with Ge : The role of a SrTiO3 buffer layer investigated using aberration-corrected STEM. In: Applied Physics Letters. 2017 ; Vol. 110, No. 25.
@article{8a09fff1642e4416b3c654e724c0f7e7,
title = "Integration of ferroelectric BaTiO3 with Ge: The role of a SrTiO3 buffer layer investigated using aberration-corrected STEM",
abstract = "The integration of semiconductors with ferroelectrics having a controlled polarization direction is an ongoing and challenging topic of research. In this work, BaTiO3 (BTO)/SrTiO3 (STO) heterostructures were grown by molecular beam epitaxy either directly with STO substrates or by using 2-nm-thick STO buffer layers on Ge(001) substrates. Sharp, chemically abrupt interfaces and c-axis-oriented BTO films for both types of heterostructures were observed using aberration-corrected scanning transmission electron microscopy and elemental mapping. Anti-phase boundaries as well as 〈100〉 misfit dislocations were present in the BTO/STO samples, with the offsets of the dislocation cores varying by distances between 1 and 5 nm away from the BTO/STO interface. Conversely, misfit dislocations were not observed in the BTO/STO/Ge structure although vertical anti-phase boundaries were still common. Overall, the results emphasize the benefits of identifying a suitable buffer layer to ensure the growth of a high quality material having the desired out-of-plane ferroelectric polarization.",
author = "Hsinwei Wu and Sirong Lu and Toshihiro Aoki and Patrick Ponath and Ekerdt, {John G.} and Demkov, {Alexander A.} and Martha McCartney and David Smith",
year = "2017",
month = "6",
day = "19",
doi = "10.1063/1.4986186",
language = "English (US)",
volume = "110",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics Publising LLC",
number = "25",

}

TY - JOUR

T1 - Integration of ferroelectric BaTiO3 with Ge

T2 - The role of a SrTiO3 buffer layer investigated using aberration-corrected STEM

AU - Wu, Hsinwei

AU - Lu, Sirong

AU - Aoki, Toshihiro

AU - Ponath, Patrick

AU - Ekerdt, John G.

AU - Demkov, Alexander A.

AU - McCartney, Martha

AU - Smith, David

PY - 2017/6/19

Y1 - 2017/6/19

N2 - The integration of semiconductors with ferroelectrics having a controlled polarization direction is an ongoing and challenging topic of research. In this work, BaTiO3 (BTO)/SrTiO3 (STO) heterostructures were grown by molecular beam epitaxy either directly with STO substrates or by using 2-nm-thick STO buffer layers on Ge(001) substrates. Sharp, chemically abrupt interfaces and c-axis-oriented BTO films for both types of heterostructures were observed using aberration-corrected scanning transmission electron microscopy and elemental mapping. Anti-phase boundaries as well as 〈100〉 misfit dislocations were present in the BTO/STO samples, with the offsets of the dislocation cores varying by distances between 1 and 5 nm away from the BTO/STO interface. Conversely, misfit dislocations were not observed in the BTO/STO/Ge structure although vertical anti-phase boundaries were still common. Overall, the results emphasize the benefits of identifying a suitable buffer layer to ensure the growth of a high quality material having the desired out-of-plane ferroelectric polarization.

AB - The integration of semiconductors with ferroelectrics having a controlled polarization direction is an ongoing and challenging topic of research. In this work, BaTiO3 (BTO)/SrTiO3 (STO) heterostructures were grown by molecular beam epitaxy either directly with STO substrates or by using 2-nm-thick STO buffer layers on Ge(001) substrates. Sharp, chemically abrupt interfaces and c-axis-oriented BTO films for both types of heterostructures were observed using aberration-corrected scanning transmission electron microscopy and elemental mapping. Anti-phase boundaries as well as 〈100〉 misfit dislocations were present in the BTO/STO samples, with the offsets of the dislocation cores varying by distances between 1 and 5 nm away from the BTO/STO interface. Conversely, misfit dislocations were not observed in the BTO/STO/Ge structure although vertical anti-phase boundaries were still common. Overall, the results emphasize the benefits of identifying a suitable buffer layer to ensure the growth of a high quality material having the desired out-of-plane ferroelectric polarization.

UR - http://www.scopus.com/inward/record.url?scp=85021064306&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85021064306&partnerID=8YFLogxK

U2 - 10.1063/1.4986186

DO - 10.1063/1.4986186

M3 - Article

AN - SCOPUS:85021064306

VL - 110

JO - Applied Physics Letters

JF - Applied Physics Letters

SN - 0003-6951

IS - 25

M1 - 252901

ER -