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Advances in creating polar structures in atomic‐layered hafnia‐zirconia (HfxZr1−xO2) films not only augurs extensive growth in studying ferroelectric nanoelectronics and neuromorphic devices, but also spurs opportunities for exploring novel integrated nanoelectromechanical systems (NEMS). Design and implementation of HfxZr1−xO2NEMS transducers necessitates accurate knowledge of elastic and electromechanical properties. Up to now, all experimental approaches for extraction of morphological content, elastic, and electromechanical properties of HfxZr1−xO2are based on solidly mounted structures, highly stressed films, and electroded architectures. Unlike HfxZr1−xO2layers embedded in electronics, NEMS transducers require free‐standing structures with highly contrasted mechanical boundaries and stress profiles. Here, a nanoresonator‐based approach for simultaneous extraction of Young's modulus and residual stress in free‐standing ferroelectric Hf0.5Zr0.5O2films is presented. High quality factor resonance modes of nanomechanical resonators created in predominantly orthorhombic Hf0.5Zr0.5O2films are measured using nondestructive optical transduction. Further, the evolution of morphology during creation of free‐standing Hf0.5Zr0.5O2structures is closely mapped using X‐ray diffraction measurements, clearly showing transformation of ferroelectric orthorhombic to nonpolar monoclinic phase upon stress relaxation. The extracted Young's modulus of 320.0 ± 29.4 GPa and residual stress ofσ = 577.4 ± 24.1 MPa show the closest match with theoretical calculations for orthorhombic Hf0.5Zr0.5O2.
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Influence of Hafnium Defects on the Optical and Structural Properties of Zirconium Nitride
Recently, the application of transition metal mononitrides (TMNs) to plasmonics and nonlinear optics has grown at an astounding rate. TiN and ZrN have emerged as the dominating materials in this direction. However, even though ZrN is reported to have lower dielectric losses and enhanced tunability in plasmonic applications when compared with TiN, the body of work regarding TiN is much more mature than that of ZrN. This imbalance of work regarding ZrN may be in part an effect of pollution in precursor materials for the fabrication of ZrN, leading to an increased imaginary part of permittivity and frustration in reproduction of ZrN with literature‐like properties. Herein, the effects of Hf defects (a common pollutant in Zr) on the optical properties of nitride films grown with radio frequency (RF) magnetron sputtering are reported. Hf defects are introduced into nitride films with a sputtering target made of the Hf‐polluted “grade 702” Zr alloy. Hf defects are found in all analyzed films with concentrations at around ≈0.5−1 at %. Chemical, structural, and optical properties of RF magnetron‐sputtered Hfx:ZryNzfilms (x ≪ y,z) are characterized and discussed.
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- Award ID(s):
- 1907423
- PAR ID:
- 10287384
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- physica status solidi (RRL) – Rapid Research Letters
- Volume:
- 15
- Issue:
- 10
- ISSN:
- 1862-6254
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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