Abstract
Epitaxial thin-film growth enables novel functionalities, particularly if significant barriers to integration with existing technologies, scalability and excessive temperature of films, can be addressed. Here, we demonstrate a step toward addressing both challenges by combining hybrid molecular beam epitaxy and atomic layer deposition to epitaxially integrate BiFeO 3 on Si wafers via a SrTiO 3 metamorphic buffer layer. The solid-solid transformation of atomic-layer-deposited amorphous Bi-Fe-O films into epitaxial BiFeO 3 thin films is investigated by in situ annealing utilizing transmission electron microscopy. The amorphous Bi-Fe-O layer undergoes a very complex crystallization process, encompassing phenomena such as reorientation, recrystallization, and grain growth. Our in situ transmission electron microscopy study revealed that a growth front of epitaxial crystallites emerged from the interface with the (001)-oriented SrTiO 3 as temperature increased, whereas randomly oriented BiFeO 3 crystallites formed simultaneously away from the interface. Structural rearrangement and recrystallization of crystallites took place at temperatures below 400 °C. At the final stage, above 400 °C, epitaxial crystallites larger than 60 nm merged into a single crystalline film. Our results demonstrate that this approach permits high-quality epitaxial integration of BiFeO 3 thin films at back-end-of-line-compatible temperatures below 500 °C on metamorphic SrTiO 3 buffer layers on Si.
| Original language | English (US) |
|---|---|
| Journal | Journal of Physical Chemistry C |
| DOIs | |
| State | Published - Jan 1 2019 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
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Toward a Low-Temperature Route for Epitaxial Integration of BiFeO 3 on Si . / Plokhikh, Aleksandr V.; Karateev, Igor A.; Falmbigl, Matthias; Vasiliev, Alexander L.; Lapano, Jason; Engel-Herbert, Roman; Spanier, Jonathan E.
In: Journal of Physical Chemistry C, 01.01.2019.Research output: Contribution to journal › Article
TY - JOUR
T1 - Toward a Low-Temperature Route for Epitaxial Integration of BiFeO 3 on Si
AU - Plokhikh, Aleksandr V.
AU - Karateev, Igor A.
AU - Falmbigl, Matthias
AU - Vasiliev, Alexander L.
AU - Lapano, Jason
AU - Engel-Herbert, Roman
AU - Spanier, Jonathan E.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Epitaxial thin-film growth enables novel functionalities, particularly if significant barriers to integration with existing technologies, scalability and excessive temperature of films, can be addressed. Here, we demonstrate a step toward addressing both challenges by combining hybrid molecular beam epitaxy and atomic layer deposition to epitaxially integrate BiFeO 3 on Si wafers via a SrTiO 3 metamorphic buffer layer. The solid-solid transformation of atomic-layer-deposited amorphous Bi-Fe-O films into epitaxial BiFeO 3 thin films is investigated by in situ annealing utilizing transmission electron microscopy. The amorphous Bi-Fe-O layer undergoes a very complex crystallization process, encompassing phenomena such as reorientation, recrystallization, and grain growth. Our in situ transmission electron microscopy study revealed that a growth front of epitaxial crystallites emerged from the interface with the (001)-oriented SrTiO 3 as temperature increased, whereas randomly oriented BiFeO 3 crystallites formed simultaneously away from the interface. Structural rearrangement and recrystallization of crystallites took place at temperatures below 400 °C. At the final stage, above 400 °C, epitaxial crystallites larger than 60 nm merged into a single crystalline film. Our results demonstrate that this approach permits high-quality epitaxial integration of BiFeO 3 thin films at back-end-of-line-compatible temperatures below 500 °C on metamorphic SrTiO 3 buffer layers on Si.
AB - Epitaxial thin-film growth enables novel functionalities, particularly if significant barriers to integration with existing technologies, scalability and excessive temperature of films, can be addressed. Here, we demonstrate a step toward addressing both challenges by combining hybrid molecular beam epitaxy and atomic layer deposition to epitaxially integrate BiFeO 3 on Si wafers via a SrTiO 3 metamorphic buffer layer. The solid-solid transformation of atomic-layer-deposited amorphous Bi-Fe-O films into epitaxial BiFeO 3 thin films is investigated by in situ annealing utilizing transmission electron microscopy. The amorphous Bi-Fe-O layer undergoes a very complex crystallization process, encompassing phenomena such as reorientation, recrystallization, and grain growth. Our in situ transmission electron microscopy study revealed that a growth front of epitaxial crystallites emerged from the interface with the (001)-oriented SrTiO 3 as temperature increased, whereas randomly oriented BiFeO 3 crystallites formed simultaneously away from the interface. Structural rearrangement and recrystallization of crystallites took place at temperatures below 400 °C. At the final stage, above 400 °C, epitaxial crystallites larger than 60 nm merged into a single crystalline film. Our results demonstrate that this approach permits high-quality epitaxial integration of BiFeO 3 thin films at back-end-of-line-compatible temperatures below 500 °C on metamorphic SrTiO 3 buffer layers on Si.
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U2 - 10.1021/acs.jpcc.8b12486
DO - 10.1021/acs.jpcc.8b12486
M3 - Article
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
ER -