Investigations of SAW delay lines on c-plane AlN/sapphire at elevated temperatures

Bruckner, Gudrun; Bardong, Jochen; Fachberger, R.; Forsén, E.; Eisele, David

doi:10.1109/freq.2010.5556280

Cited by 7 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Post-analysis shows no degradation of the AlN surface. Unfortunately, no intermediate measurement was performed between 630 and 858°C which would have clarified the operating temperature limit [21]. Note however that these results are in perfect agreement with some previous studies about the limits of platinum IDTs estimated at 750 °C [22].…”

Section: Background and State Of The Artsupporting

confidence: 87%

Is AlN/Sapphire bilayer structure an alternative to langasite for ultra-high-temperature SAW applications?

Aubert¹,

Elmazria²,

Bardong³

et al. 2011

2011 IEEE International Ultrasonics Symposium

Self Cite

View full text Add to dashboard Cite

This paper explores the potentiality to use AlN/sapphire structure as alternative piezoelectric material to langasite (LGS) for high-temperature SAW applications. In situ SAW measurements performed in vacuum up to 1050°C attest that AlN/Sapphire is more stable than LGS in such conditions. While in the case of LGS, the signal is completely lost after 8 hours at 1050 °C, the device based on AlN/sapphire stays alive for 60 hours at this extreme temperature. Moreover, the degradation is attributed not to AlN but to the agglomeration phenomena undergone by the Iridium IDTs. The AlN/Sapphire structure shows also, between room temperature and at least 1050°C, a great sensitivity to temperature as well as a good linearity, which is very suitable for temperature sensor applications.

show abstract

Section: Background and State Of The Artsupporting

confidence: 87%

Is AlN/Sapphire bilayer structure an alternative to langasite for ultra-high-temperature SAW applications?

Aubert¹,

Elmazria²,

Bardong³

et al. 2011

2011 IEEE International Ultrasonics Symposium

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, it is necessary to find alternatives to LGS for specific applications. Recent studies have shown that AlN/Sapphire is a promising piezoelectric structure for hightemperature SAW applications [7][8][9][10][11][12], even in the GHz-range [13][14]. However, the oxidation of AlN prohibits the use of this structure above 700°C in air [11].…”

Section: Introductionmentioning

confidence: 99%

AlN/IDT/AlN/Sapphire SAW Heterostructure for High-Temperature Applications

Legrani

Aubert

Elmazria

et al. 2016

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

View full text Add to dashboard Cite

Recent studies have evidenced that Pt/AlN/Sapphire surface acoustic wave (SAW) devices are promising for high-temperature high-frequency applications. However, they cannot be used above 700°C in air atmosphere as the Pt interdigital transducers (IDTs) agglomerate and the AlN layer oxidizes in such conditions. In this paper, we explore the possibility to use an AlN protective overlayer to concurrently hinder these phenomena. To do so, AlN/IDT/AlN/Sapphire heterostructures undergo successive annealing steps from 800°C to 1000°C in air atmosphere. The impact of each step on the morphology, microstructure, and phase composition of AlN and Pt films is evaluated using optical microscopy, scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD), and secondary ion mass spectroscopy (SIMS). Finally, acoustical performance at room temperature of both protected and unprotected SAW devices are compared, as well as the effects of annealing on these performance. These investigations show that the use of an overlayer is one possible solution to strongly hinder the Pt IDTs agglomeration up to 1000°C. Moreover, AlN/IDT/AlN/Sapphire SAW heterostructures show promising performances in terms of stability up to 800°C. At higher temperatures, the oxidation of AlN is more intense and makes it inappropriate to be used as a protective layer.

show abstract

“…By now, all SAW devices are fabricated on the stiff substrates instead of flexible's, suah as LiNbO 3 [2], Piezoelectric (PE) thin films on Si wafer [3,4], diamond [5], Al 2 O 3 [6] and so on. SAW on flexible substrate is cheaper and can be bent easily, which is fitted for portable microfluidic applications, such as wrist health-care monitor.…”

Section: Introductionmentioning

confidence: 99%

Flexible Surface Acoustic Wave Device with AlN Film on Polymer Substrate

Zhou

Dong

Jin

et al. 2012

Journal of Control Science and Engineering

View full text Add to dashboard Cite

Surface acoustic wave device with c-axis-oriented aluminum nitride (AlN) piezoelectric thin films on polymer substrates can be potentially used for development of flexible sensors, flexible microfluidic applications, microsystems, and lab-on-chip systems. In this work, the AlN films have been successfully deposited on polymer substrates using the DC reactive magnetron-sputtering method at room temperature, and the XRD, SEM, and AFM methods reveal that low deposition pressure is beneficial to the highly c-axis-oriented AlN film on polymer substrates. Studies toward the development of AlN thin film-based flexible surface acoustic wave devices on the polymer substrates are initiated and the experimental and simulated results demonstrate the devices showing the acoustic wave velocity of 9000-10000 m/s, which indicate the AlN lamb wave.

show abstract

Investigations of SAW delay lines on c-plane AlN/sapphire at elevated temperatures

Cited by 7 publications

References 11 publications

Is AlN/Sapphire bilayer structure an alternative to langasite for ultra-high-temperature SAW applications?

Is AlN/Sapphire bilayer structure an alternative to langasite for ultra-high-temperature SAW applications?

AlN/IDT/AlN/Sapphire SAW Heterostructure for High-Temperature Applications

Flexible Surface Acoustic Wave Device with AlN Film on Polymer Substrate

Contact Info

Product

Resources

About