Piezoelectric Aluminium Scandium Nitride (AlScN) Thin Films

Piezoelectric Aluminium Scandium Nitride (AlScN) Thin Films PDF Author: Agne Zukauskaite
Publisher: Mdpi AG
ISBN: 9783036563671
Category : Science
Languages : en
Pages : 0

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Book Description
Recently, aluminium scandium nitride (AlScN) emerged as a material with superior properties compared to aluminium nitride (AlN). Substituting Al with Sc in AlN leads to a dramatic increase in the piezoelectric coefficient as well as in electromechanical coupling. This discovery finally allowed us to overcome the limitations of AlN thin films in various piezoelectric applications while still enabling us to benefit from all of the advantages of the parent material system, such as a high temperature stability, CMOS compatibility, and good mechanical properties. Potential applications include RF filters (bulk acoustic wave (BAW) or surface acoustic wave (SAW) resonators), energy harvesting, sensing applications, and infra-red detectors. The recent progress in MOCVD- and MBE-grown AlScN has led to high-frequency and -power electronics, (high-electron-mobility transistors (HEMTs)). AlScN is the first wurtzite III-nitride where ferroelectric switching was observed, allowing for many new possible applications in semiconductor memories additionally, it enables the additional functionality of switching to applications where piezoelectric materials are already in use. This Special Issue was very successful in covering all of the main aspects of AlScN research, including its growth, the fundamental and application-relevant properties, and device fabrication and characterization. We can see that AlScN technology is mature enough to be utilized in wafer-level material development and complicated devices, but there is still much to discover in terms of deposition process control, anisotropy, and, in particular, ferroelectric behavior.

Piezoelectric Aluminium Scandium Nitride (AlScN) Thin Films

Piezoelectric Aluminium Scandium Nitride (AlScN) Thin Films PDF Author: Agne Zukauskaite
Publisher: Mdpi AG
ISBN: 9783036563671
Category : Science
Languages : en
Pages : 0

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Book Description
Recently, aluminium scandium nitride (AlScN) emerged as a material with superior properties compared to aluminium nitride (AlN). Substituting Al with Sc in AlN leads to a dramatic increase in the piezoelectric coefficient as well as in electromechanical coupling. This discovery finally allowed us to overcome the limitations of AlN thin films in various piezoelectric applications while still enabling us to benefit from all of the advantages of the parent material system, such as a high temperature stability, CMOS compatibility, and good mechanical properties. Potential applications include RF filters (bulk acoustic wave (BAW) or surface acoustic wave (SAW) resonators), energy harvesting, sensing applications, and infra-red detectors. The recent progress in MOCVD- and MBE-grown AlScN has led to high-frequency and -power electronics, (high-electron-mobility transistors (HEMTs)). AlScN is the first wurtzite III-nitride where ferroelectric switching was observed, allowing for many new possible applications in semiconductor memories additionally, it enables the additional functionality of switching to applications where piezoelectric materials are already in use. This Special Issue was very successful in covering all of the main aspects of AlScN research, including its growth, the fundamental and application-relevant properties, and device fabrication and characterization. We can see that AlScN technology is mature enough to be utilized in wafer-level material development and complicated devices, but there is still much to discover in terms of deposition process control, anisotropy, and, in particular, ferroelectric behavior.

Development of High Performance Piezoelectric AlScN for Microelectromechanical Systems: Towards a Ferroelectric Wurtzite Structure

Development of High Performance Piezoelectric AlScN for Microelectromechanical Systems: Towards a Ferroelectric Wurtzite Structure PDF Author: Simon Fichtner
Publisher: BoD – Books on Demand
ISBN: 3750431426
Category : Science
Languages : en
Pages : 180

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Book Description
The usage of piezoelectric and ferroelectric thin films is a promising approach to significantly increase the functionality of microelectromechanical systems (MEMS) as well as of microelectronics in general. Since the device performance thus becomes directly connected to the properties of the functional film, new as well as improved piezoelectric and ferroelectric materials can allow substantial technological innovation. This dissertation focused on enhancing the piezoelectric properties of AlN by forming solid solutions with ScN and includes the first experimental observation of ferroelectricity in AlScN, and thus the first discovery of ferroelectricity in a III-V semiconductor based material in general. Compared to AlN, piezoelectric coefficients that are up to 450% higher were realized in AlScN, with d33f reaching a maximum of 17.2 pm/V and e31f reaching 3.2 C/m2. In this context, the identification and subsequent rectification of a major morphological instability in AlScN that becomes more pronounced with increasing Sc content was reported. Thus, films free of morphological inhomogeneities with close to ideal piezoelectric properties could be deposited up to 0.43% ScN. Control of the intrinsic film stress was demonstrated over a wide range from strongly tensile to strongly compressive for all the investigated Sc contents. The improved piezoelectric coefficients together with the possibility of stress control allowed the fabrication of suspended MEMS structures with electromechanical coupling coefficients improved by more than 320% relative to AlN. Ferroelectrictiy in AlScN was observed starting at ScN contents of 27%. Its emergence was connected to the same gradual evolution from the initial wurtzite structure to the layered hexagonal structure that also causes the enhanced piezoelectric coefficients while increasing the Sc content. Ferroelectric AlScN allowed the first experimental observation of the spontaneous polarization of the wurtzite structure and confirms that this polarization is more than one order of magnitude above most previous theoretical predictions. The large, tunable coercive fields and polarization constants together with the broad linear strain intervals, a paraelectric transition temperature above 600°C as well as the technological compatibility of the III-nitrides lead to a combination of exceptional properties that was previously inaccessible in ferroelectric thin films.

Piezoelectric Aluminum Nitride Thin Films by PECVD

Piezoelectric Aluminum Nitride Thin Films by PECVD PDF Author: Gustavo Sanchez Mathon
Publisher:
ISBN:
Category :
Languages : en
Pages : 432

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Book Description
Polycrystalline aluminum nitride thin films were produced with a microwave-plasma enhanced chemical vapor deposition technique. The plasma-injector distance, the substrate temperature and the RF bias were the main variables which allowed achieving this objective. At the time, it was possible to control the preferential orientation as 0001 or 1010, both interesting for piezoelectric applications. The growth mechanisms that conducted to film microstructure development under different process conditions were explained, enriched by the comparison with a physical vapor deposition sputtering technique. The obtained films were characterized in their piezoelectric performance, including the construction of surface acoustic wave devices and bulk acoustic wave devices. Adequate piezoelectric response and acoustic velocities were obtained for 0001 oriented films, while 1010 oriented films did not show piezoelectric response under the configurations essayed. An extensive analysis was done in order to explain these behaviors.

2021 IEEE 34th International Conference on Micro Electro Mechanical Systems (MEMS).

2021 IEEE 34th International Conference on Micro Electro Mechanical Systems (MEMS). PDF Author:
Publisher:
ISBN: 9781665419123
Category :
Languages : en
Pages :

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Aluminum Nitride Thin Films and Structures for Piezoelectric Microelectromechanical Systems (PMEMS) Applications

Aluminum Nitride Thin Films and Structures for Piezoelectric Microelectromechanical Systems (PMEMS) Applications PDF Author: Adam Kabulski
Publisher:
ISBN:
Category : Aluminum nitride
Languages : en
Pages :

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Effect of Interface Fields on the Piezoelectric Response of Aluminum Nitride Thin Films

Effect of Interface Fields on the Piezoelectric Response of Aluminum Nitride Thin Films PDF Author: John Preston Harman
Publisher:
ISBN:
Category : Aluminum nitride
Languages : en
Pages :

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Aluminum Nitride Piezoelectric Thin Films Reactively Deposited in Closed Field Unbalanced Magnetron Sputtering for Elevated Temperature 'smart' Tribological Applications

Aluminum Nitride Piezoelectric Thin Films Reactively Deposited in Closed Field Unbalanced Magnetron Sputtering for Elevated Temperature 'smart' Tribological Applications PDF Author: Masood Hasheminiasari
Publisher:
ISBN:
Category : Aluminum nitride
Languages : en
Pages : 168

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Piezoelectric Sensors

Piezoelectric Sensors PDF Author: Peter Lieberzeit
Publisher: Springer Nature
ISBN: 3031537858
Category :
Languages : en
Pages : 344

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High Temperature Annealing Studies on the Piezoelectric Properties of Thin Aluminum Nitride Films

High Temperature Annealing Studies on the Piezoelectric Properties of Thin Aluminum Nitride Films PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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A Rapid Thermal Annealing (RTA) system was used to anneal sputtered and MOVPE grown Aluminum Nitride (AlN) thin films at temperatures up to 1000°C in ambient and controlled environments. According to Energy Dispersive X-Ray Analysis (EDAX), the films annealed in an ambient environment rapidly oxidize after five minutes at 1000°C. Below 1000°C the films oxidized linearly as a function of annealing temperature which is consistent with what has been reported in literature [1]. Laser Doppler Vibrometry (LDV) was used to measure the piezoelectric coefficient, d33, of these films. Films annealed in an ambient environment had a weak piezoelectric response indicating that oxidation on the surface of the film reduces the value of d33. A high temperature furnace has been built that is capable of taking in-situ measurements of the piezoelectric response of AlN films. In-situ d33 measurements are recorded up to 300°C for both sputtered and MOVPE-grown AlN thin films. The measured piezoelectric response appears to increase with temperature up to 300°C possibly due to stress in the film.

High Temperature Studies of Thin Film Aluminum Nitride and Piezoelectric Characterization of Mesa Structures

High Temperature Studies of Thin Film Aluminum Nitride and Piezoelectric Characterization of Mesa Structures PDF Author:
Publisher:
ISBN:
Category : Microelectromechanical systems
Languages : en
Pages :

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