Nanoscale Structural and Chemical Properties of Ferroelectric Aluminum Scandium Nitride Thin Films

Pariasadat Musavigharavi; Andrew C. Meng; Dixiong Wang; Jeffery Zheng; Alexandre C. Foucher; Roy H. Olsson; Eric A. Stach

doi:10.1021/acs.jpcc.1c01523

Nanoscale Structural and Chemical Properties of Ferroelectric Aluminum Scandium Nitride Thin Films

Pariasadat Musavigharavi, Andrew C. Meng, Dixiong Wang, Jeffery Zheng, Alexandre C. Foucher, Roy H. Olsson, Eric A. Stach

Research output: Contribution to journal › Article › peer-review

19 Scopus citations

Abstract

The local atomic structure and nanoscale chemistry of ferroelectric aluminum scandium nitride thin films (Al_1-xSc_xN) are examined using advanced transmission electron microscopy (TEM) techniques. An Al_1-xSc_xN (x= 0.36) film of ∼20 nm thickness was grown on a Pt(111)/Ti/SiO₂/Si(100) substrate via pulsed DC co-sputtering. Here, we describe how the Sc alloying concentration and strain distribution through the AlScN film thickness become more pronounced in ultrathin films. The homogeneous distribution of scandium and the formation of defects in the epitaxial growth of 2.1% lattice-mismatched AlScN on Pt are reported. In this paper, the “four-dimensional scanning TEM” (4D-STEM) technique is employed to systematically investigate the nanoscale order by measuring the average spacing between atoms within certain regions in the film and determining the strain. The strain map confirms a significant increase in the out-of-plane component of the lattice parameter (∼9%) at the AlScN/Pt interface. The lattice parameter in the Pt template decreases as a function of distance from the Pt/Si interface. The study of the atomic crystal structure and the chemical composition of the AlScN thin film provides useful understanding toward the applications of this material in ferroelectric memories and microelectromechanical systems.

Original language	English
Pages (from-to)	14394-14400
Number of pages	7
Journal	Journal of Physical Chemistry C
Volume	125
Issue number	26
DOIs	https://doi.org/10.1021/acs.jpcc.1c01523
State	Published - Jul 8 2021
Externally published	Yes

Funding

This work was supported in part by the Semiconductor Research Corporation (SRC) and in part by the DARPA Tunable Ferroelectric Nitrides (TUFEN) program under agreement no. HR00112090046. The authors would also like to acknowledge Kim Kisslinger at the Center for Functional Nanomaterials (CFN), Brookhaven National Laboratory for TEM sample preparation. This work was carried out in part at the Singh Center for Nanotechnology, supported by the NSF National Nanotechnology Coordinated Infrastructure Program under grant NNCI-1542153. The authors acknowledge the use of facilities and instrumentation supported by the NSF University of Pennsylvania Materials Research Science and Engineering Center (MRSEC) (DMR-1720530). A.C.F. acknowledges support from Integrated Mesoscale Architectures for Sustainable Catalysis (IMASC), an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences under award no. DE-SC0012573.

Funders	Funder number
Integrated Mesoscale Architectures for Sustainable Catalysis
NSF University of Pennsylvania Materials Research Science and Engineering Center
National Science Foundation	NNCI-1542153
National Science Foundation
U.S. Department of Energy
Semiconductor Research Corporation
Defense Advanced Research Projects Agency	HR00112090046
Defense Advanced Research Projects Agency
Office of Science
Basic Energy Sciences	DE-SC0012573
Basic Energy Sciences
Materials Research Science and Engineering Center, Harvard University	DMR-1720530
Materials Research Science and Engineering Center, Harvard University

Access to Document

10.1021/acs.jpcc.1c01523

Cite this

@article{75e7f15c50794603b66cd11d573e429e,

title = "Nanoscale Structural and Chemical Properties of Ferroelectric Aluminum Scandium Nitride Thin Films",

abstract = "The local atomic structure and nanoscale chemistry of ferroelectric aluminum scandium nitride thin films (Al1-xScxN) are examined using advanced transmission electron microscopy (TEM) techniques. An Al1-xScxN (x= 0.36) film of ∼20 nm thickness was grown on a Pt(111)/Ti/SiO2/Si(100) substrate via pulsed DC co-sputtering. Here, we describe how the Sc alloying concentration and strain distribution through the AlScN film thickness become more pronounced in ultrathin films. The homogeneous distribution of scandium and the formation of defects in the epitaxial growth of 2.1% lattice-mismatched AlScN on Pt are reported. In this paper, the “four-dimensional scanning TEM” (4D-STEM) technique is employed to systematically investigate the nanoscale order by measuring the average spacing between atoms within certain regions in the film and determining the strain. The strain map confirms a significant increase in the out-of-plane component of the lattice parameter (∼9%) at the AlScN/Pt interface. The lattice parameter in the Pt template decreases as a function of distance from the Pt/Si interface. The study of the atomic crystal structure and the chemical composition of the AlScN thin film provides useful understanding toward the applications of this material in ferroelectric memories and microelectromechanical systems.",

author = "Pariasadat Musavigharavi and Meng, {Andrew C.} and Dixiong Wang and Jeffery Zheng and Foucher, {Alexandre C.} and Olsson, {Roy H.} and Stach, {Eric A.}",

note = "Publisher Copyright: {\textcopyright} 2021 American Chemical Society",

year = "2021",

month = jul,

day = "8",

doi = "10.1021/acs.jpcc.1c01523",

language = "English",

volume = "125",

pages = "14394--14400",

journal = "Journal of Physical Chemistry C",

issn = "1932-7447",

publisher = "American Chemical Society",

number = "26",

}

TY - JOUR

T1 - Nanoscale Structural and Chemical Properties of Ferroelectric Aluminum Scandium Nitride Thin Films

AU - Musavigharavi, Pariasadat

AU - Meng, Andrew C.

AU - Wang, Dixiong

AU - Zheng, Jeffery

AU - Foucher, Alexandre C.

AU - Olsson, Roy H.

AU - Stach, Eric A.

PY - 2021/7/8

Y1 - 2021/7/8

N2 - The local atomic structure and nanoscale chemistry of ferroelectric aluminum scandium nitride thin films (Al1-xScxN) are examined using advanced transmission electron microscopy (TEM) techniques. An Al1-xScxN (x= 0.36) film of ∼20 nm thickness was grown on a Pt(111)/Ti/SiO2/Si(100) substrate via pulsed DC co-sputtering. Here, we describe how the Sc alloying concentration and strain distribution through the AlScN film thickness become more pronounced in ultrathin films. The homogeneous distribution of scandium and the formation of defects in the epitaxial growth of 2.1% lattice-mismatched AlScN on Pt are reported. In this paper, the “four-dimensional scanning TEM” (4D-STEM) technique is employed to systematically investigate the nanoscale order by measuring the average spacing between atoms within certain regions in the film and determining the strain. The strain map confirms a significant increase in the out-of-plane component of the lattice parameter (∼9%) at the AlScN/Pt interface. The lattice parameter in the Pt template decreases as a function of distance from the Pt/Si interface. The study of the atomic crystal structure and the chemical composition of the AlScN thin film provides useful understanding toward the applications of this material in ferroelectric memories and microelectromechanical systems.

AB - The local atomic structure and nanoscale chemistry of ferroelectric aluminum scandium nitride thin films (Al1-xScxN) are examined using advanced transmission electron microscopy (TEM) techniques. An Al1-xScxN (x= 0.36) film of ∼20 nm thickness was grown on a Pt(111)/Ti/SiO2/Si(100) substrate via pulsed DC co-sputtering. Here, we describe how the Sc alloying concentration and strain distribution through the AlScN film thickness become more pronounced in ultrathin films. The homogeneous distribution of scandium and the formation of defects in the epitaxial growth of 2.1% lattice-mismatched AlScN on Pt are reported. In this paper, the “four-dimensional scanning TEM” (4D-STEM) technique is employed to systematically investigate the nanoscale order by measuring the average spacing between atoms within certain regions in the film and determining the strain. The strain map confirms a significant increase in the out-of-plane component of the lattice parameter (∼9%) at the AlScN/Pt interface. The lattice parameter in the Pt template decreases as a function of distance from the Pt/Si interface. The study of the atomic crystal structure and the chemical composition of the AlScN thin film provides useful understanding toward the applications of this material in ferroelectric memories and microelectromechanical systems.

UR - http://www.scopus.com/inward/record.url?scp=85110404520&partnerID=8YFLogxK

U2 - 10.1021/acs.jpcc.1c01523

DO - 10.1021/acs.jpcc.1c01523

M3 - Article

AN - SCOPUS:85110404520

SN - 1932-7447

VL - 125

SP - 14394

EP - 14400

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 26

ER -

Nanoscale Structural and Chemical Properties of Ferroelectric Aluminum Scandium Nitride Thin Films

Abstract

Funding

Access to Document

Other files and links

Fingerprint

Cite this