Elastic modulus and coefficient of thermal expansion of piezoelectric Al<sub>1−x</sub>Sc<sub>x</sub>N (up to x = 0.41) thin films

Lu, Yuan; Reusch, Markus; Kurz, Nicolas; Ding, Anli; Christoph, Tim; Prescher, Mario; Kirste, Lutz; Ambacher, O.; Žukauskaitė, Agnė

doi:10.1063/1.5040190

Cited by 89 publications

(49 citation statements)

References 30 publications

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“…The greater improvements in the piezoelectric response were achieved after annealing at temperatures between 500°C and 600°C for 15 min to 30 min. These results show that post-deposition annealing enables achieving remarkably higher k 2 values than those reported for AlScN films of similar compositions [13,14] as well as those predicted from ab-initio calculations [15].…”

Section: B Effects Of Vacuum Annealing On Samplessupporting

confidence: 72%

Effects of Post-Deposition Vacuum Annealing on the Piezoelectric Properties of AlScN Thin Films Sputtered on 200 Mm Production Wafers

Clément

Olivares

Mirea

et al. 2018

2018 IEEE International Ultrasonics Symposium (IUS)

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Sc-doped A1N polycrystalline films are attractive active layers for high frequency (GHz range) acoustic resonators owing to the significant rise in the material piezoelectric activity with the increasing Sc content. AlScN films are sputtered on 200 mm Si wafers using configurable cathode containing a variable number of embedded Sc pellets which allows controlling both the Sc content in the films and the composition homogeneity across the wafer. The method is implemented in an Endeavor-AT™ cluster tool from OEM Group adapted for sputtering on 200 mm wafers. The piezoelectric activity of the as-deposited AlScN films appears to improve after a 15-minute post-deposition annealing at 600°C, leading to a 20% increase in the electromechanical coupling factor.

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Section: B Effects Of Vacuum Annealing On Samplessupporting

confidence: 72%

Effects of Post-Deposition Vacuum Annealing on the Piezoelectric Properties of AlScN Thin Films Sputtered on 200 Mm Production Wafers

Clément

Olivares

Mirea

et al. 2018

2018 IEEE International Ultrasonics Symposium (IUS)

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“…Compressive stress occurs in films because of mismatched coefficients of thermal expansion. The CTE for Al 1−x Sc x N (x = 0.23) is 4.95 ± 0.26 × 10 −6 C −1 [24] and the CTE for Al thin films ranges from 18.23 × 10 −6 C −1 to 29.97 × 10 −6 C −1 [25]. The CTE for Mo is 5.56 × 10 −6 C −1 [26].…”

Section: A Surface Characterizationmentioning

confidence: 96%

Characterization of AlScN-Based Multilayer Systems for Piezoelectric Micromachined Ultrasound Transducer (pMUT) Fabrication

Bespalova

Österlund

Ross

et al. 2021

J. Microelectromech. Syst.

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Scandium-alloyed aluminum nitride (AlScN) is a potential material for micro-electromechanical systems because of its unique advantages, such as strong piezoelectric effect and high thermal stability. However, issues related to its stability and interaction with other materials in multilayer systems require investigation. The formation of new phases at the interface between piezomaterial and electrode material can lead to the device failure. In this study, multilayer structures Si substrate/AlN/Ti-Mo/Al 0.8 Sc 0.2 N/top electrode (TE) were studied after annealing at a wide range of temperatures and durations. Four different TE materials (i.e. Al, AlSi (1%), Mo/Al, and Mo) were examined to determine the most reliable electrode material for the structure. The phase stability, interfacial quality, and piezoelectric response of the multilayer systems after thermal annealing were investigated. The structure with Mo TE layer was stable after annealing at 800 • C for 300 h and at 1000 • C for 100 h. None of the structures formed any new phases at the interface between the electrode layer and AlScN. The transverse piezoelectric coefficient (e 31,f) was determined for Al 0.8 Sc 0.2 N before and after annealing. The absolute value of the e 31,f was −1.39 C/m 2 for as-deposited structure and −1.67 C/m 2 for the same structure annealed for 300 h at 800 • C.

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“…The first one is the angle-dependent anisotropy. The sputtered material with typical grain sizes less than 100 nm exhibits twisted pillars [45] with strong c-axis orientation, which can also be seen in their own X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements. Thus, an isotropic Young's modulus is expected in contrast to the calculated moduli.…”

Section: Resultsmentioning

confidence: 83%

Automated Parameter Extraction Of ScAlN MEMS Devices Using An Extended Euler–Bernoulli Beam Theory

Krey

Hähnlein

Tonisch

et al. 2020

Sensors

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Magnetoelectric sensors provide the ability to measure magnetic fields down to the pico tesla range and are currently the subject of intense research. Such sensors usually combine a piezoelectric and a magnetostrictive material, so that magnetically induced stresses can be measured electrically. Scandium aluminium nitride gained a lot of attraction in the last few years due to its enhanced piezoelectric properties. Its usage as resonantly driven microelectromechanical system (MEMS) in such sensors is accompanied by a manifold of influences from crystal growth leading to impacts on the electrical and mechanical parameters. Usual investigations via nanoindentation allow a fast determination of mechanical properties with the disadvantage of lacking the access to the anisotropy of specific properties. Such anisotropy effects are investigated in this work in terms of the Young’s modulus and the strain on basis of a MEMS structures through a newly developed fully automated procedure of eigenfrequency fitting based on a new non-Lorentzian fit function and subsequent analysis using an extended Euler–Bernoulli theory. The introduced procedure is able to increase the resolution of the derived parameters compared to the common nanoindentation technique and hence allows detailed investigations of the behavior of magnetoelectric sensors, especially of the magnetic field dependent Young‘s modulus of the magnetostrictive layer.

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Elastic modulus and coefficient of thermal expansion of piezoelectric Al_1−xSc_xN (up to x = 0.41) thin films

Cited by 89 publications

References 30 publications

Effects of Post-Deposition Vacuum Annealing on the Piezoelectric Properties of AlScN Thin Films Sputtered on 200 Mm Production Wafers

Effects of Post-Deposition Vacuum Annealing on the Piezoelectric Properties of AlScN Thin Films Sputtered on 200 Mm Production Wafers

Characterization of AlScN-Based Multilayer Systems for Piezoelectric Micromachined Ultrasound Transducer (pMUT) Fabrication

Automated Parameter Extraction Of ScAlN MEMS Devices Using An Extended Euler–Bernoulli Beam Theory

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Elastic modulus and coefficient of thermal expansion of piezoelectric Al1−xScxN (up to x = 0.41) thin films

Cited by 89 publications

References 30 publications

Effects of Post-Deposition Vacuum Annealing on the Piezoelectric Properties of AlScN Thin Films Sputtered on 200 Mm Production Wafers

Effects of Post-Deposition Vacuum Annealing on the Piezoelectric Properties of AlScN Thin Films Sputtered on 200 Mm Production Wafers

Characterization of AlScN-Based Multilayer Systems for Piezoelectric Micromachined Ultrasound Transducer (pMUT) Fabrication

Automated Parameter Extraction Of ScAlN MEMS Devices Using An Extended Euler–Bernoulli Beam Theory

Contact Info

Product

Resources

About

Elastic modulus and coefficient of thermal expansion of piezoelectric Al_1−xSc_xN (up to x = 0.41) thin films