Temperature‐Dependent Phase Transitions in HfxZr1‐xO2 Mixed Oxides: Indications of a Proper Ferroelectric Material. (17th May 2022)

• Record Type: Journal Article
• Authors: Schroeder, Uwe; Mittmann, Terence; Materano, Monica; Lomenzo, Patrick D.; Edgington, Patrick; Lee, Young H.; Alotaibi, Meshari; West, Anthony R.; Mikolajick, Thomas; Kersch, Alfred; Jones, Jacob L.
• Is Part Of: Advanced Electronic Materials. Volume 8:Number 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-17
• Subjects: Curie–Weiss law -- ferroelectric materials -- hafnium oxide -- phase transition in doped HfO 2 and ZrO 2 -- zirconium oxide; Materials -- Electric properties -- Periodicals; Materials science -- Periodicals; Magnetic materials -- Periodicals; Electronic apparatus and appliances -- Periodicals; 537
• DOI: 10.1002/aelm.202200265
• Languages: English
• ISSNs: 2199-160X

Abstract

Abstract: Knowledge about phase transitions in doped HfO2 and ZrO2 ‐based films is crucial for developing future ferroelectric devices. These devices should perform in ambient temperature ranges with no degradation of device performance. Here, the phase transition from the polar orthorhombic to the nonpolar tetragonal phase in thin films is of significant interest. Detailed electrical and structural characterization is performed on 10 nm mixed Hfx Zr1‐x O2 binary oxides with different ZrO2 in HfO2 and small changes in oxygen content. Both dopant and oxygen content directly impact the phase transition temperature between the polar and nonpolar phase. A first‐order phase transition with thermal hysteresis is observed from the nonpolar to the polar phase with a maximum in the dielectric constant. The observed phase transition temperatures confirm trends as obtained by DFT calculations. Based on the outcome of the measurements, the classification of the ferroelectric material is discussed. Abstract : Curie temperatures of CMOS compatible ferroelectric Hfx Zr1‐x Oy capacitors are investigated and found to be promising for semiconductor applications. The dependence of the phase transition on composition in relation to reversible and irreversible transitions is shown and compared with DFT simulations. The material system is classified as a proper ferroelectric material with first‐order phase transition.