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Identification of structural phases in ferroelectric hafnium zirconium oxide by density-functional-theory-assisted EXAFS analysis.
- Source :
- Applied Physics Letters; 3/7/2021, Vol. 118 Issue 9, p1-7, 7p
- Publication Year :
- 2021
-
Abstract
- Crystalline phase identification for hafnium-based ferroelectrics by diffraction techniques has been elusive. We use density-functional-theory (DFT)-assisted extended X-ray absorption fine-structure spectroscopy (EXAFS) to determine the crystal symmetry of thin hafnium zirconium oxide (Hf<subscript>0.46</subscript>Zr<subscript>0.54</subscript>O<subscript>2</subscript>) films grown by atomic layer deposition. Ferroelectric switching in TiN/Hf<subscript>0.46</subscript>Zr<subscript>0.54</subscript>O<subscript>2</subscript>/TiN metal–insulator–metal capacitors is verified. Grazing-incidence fluorescence-yield mode Hf L<subscript>3</subscript> and Zr K absorption edge EXAFS data are compared with reference data calculated from DFT-based atomic coordinates for various structural phases of Hf<subscript>0.5</subscript>Zr<subscript>0.5</subscript>O<subscript>2</subscript>. Via EXAFS multiphase fitting, we confirm that the frequently invoked polar orthorhombic Pca2<subscript>1</subscript> phase is present in ferroelectric hafnium zirconium oxide, along with an equal amount of the nonpolar monoclinic P2<subscript>1</subscript>/c phase. For comparison, we verify that paraelectric HfO<subscript>2</subscript> films exhibit the P2<subscript>1</subscript>/c phase. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 118
- Issue :
- 9
- Database :
- Complementary Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 149128853
- Full Text :
- https://doi.org/10.1063/5.0038674