Curie Temperature characterization of submicronic LiTaO3 thin film in POI structure by in-situ Raman spectroscopy and X-ray diffraction

International audienceCaractérisation de la température de Curie d'un film mince LiTaO3 submicronique dans la structure POI par spectroscopie Raman in situ et diffraction des rayons

Smart Cut™ Piezo On Insulator (POI) substrates for high performances SAW components

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Electrode Confined Acoustic Wave (ECAW) devices for Ultra High Band applications

International audienceThis paper presents a new approach to increase the operational frequency of Surface Acoustic Wave devices. The excitation of a new type of mode called ECAW ( Electrode Confined Acoustic Wave) exhibiting a phase velocity much higher than the one of a standard SAW is demonstrated. In this context, a new composite substrate is considered to guarantee a perfect spectral purity. Therefore, Piezo-On-Glass substrates are manufactured and used for the manufacturing of ECAW device prototypes. Preliminary results show a frequency at 2.5 GHz with an IDT pitch equal to 2 μm. In terms of power handling, widest tested components successfully handle up to 36 dBm without destruction of the devices

New generation of composite substrates based on a layer of LiTaO3 on silicon for surface acoustic waves components

International audienceThe development of new generations of telecommunication systems requires more and more components and radio-frequency (RF) modules to select and the process signals supporting the information. The solution the most used for this kind of application is always based on the principle of surface acoustic waves (SAW) and its associated components, taking into account their unique spectral quality (insertion losses, out of band rejection, group delay?), their design flexibility and their compactness for L- and S-bands. Although still commonly used today, filters on single-crystals such as lithium tantalate (LiTaO3) and lithium niobate (LiNbO3) cannot be used for future RF modules since the intrinsic stability of these substrates is far from being adapted to meet the challenges of modern telecommunications. To respond to this demands, a new generation of substrates is necessary. The main idea of the work presented here then consists in combining a thin piezoelectric film and a substrate having a thermal expansion much lower than that of piezoelectric layer. This kind of structure is named POI for Piezoelectric-On-Insulator. Although studied for years, this solution is meeting a growing interest given the advantages it offers for SAW filters. We propose to present a review of the concepts as well as the work which led to these developments. An overview of the different technologies enabling the manufacture of these composite substrates will also be proposed. Figures of merit on test vehicles as well as examples of applications will be presented in order to highlight the potential of this new technological solution. Finally, we will conclude on the interest and prospects of such a structure for the telecommunications and wireless sensors, compared to single-crystals substrates

4.2 GHz LiNbO 3 Film Bulk Acoustic Resonator

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Supplementary document for Temporal Localized Turing Patterns in Mode-locked Semiconductor Lasers - 6108005.pdf

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8 inch Surface and Bulk Acoustic Wave devices based on POI substrate for 5G

International audienceThe availability of Piezoelectric-On-Insulator (POI) substrates, made of a thin single crystal LiTaO3 film atop a silicon substrate, has promoted the development of innovative Surface and Bulk Acoustic Wave devices (SAW and BAW). However, these substrates are so far only commercially available in 4 and 6 inch diameter. In this work, we successfully fabricate acoustic devices based on 8-inch POI substrates. SAW resonators display an electromechanical coupling coefficient of 8.83% at a resonance frequency of 1.6 GHz. Film Bulk Acoustic Resonator (FBAR) and Solidly Mounted Resonator (SMR), which integrate more complex layer stacks, such as a buried electrode and acoustic isolation structures, have been also fabricated. The FBAR exhibits a single resonance at 2.8 GHz, with an electromechanical coupling coefficient of 8.75% and a quality factor close to 190. The SMR based on a dielectric (AlN/SiO2) Bragg mirror exhibits a coupling coefficient of 6.1% and a quality factor of 405 at 4 GHz. A Temperature Coefficient of Frequency (TCF) of -14 and -22 ppm/°C at resonance and antiresonance are obtained respectively. Such TCF values are among the lowest ever reported for LiNbO3 and LiTaO3 BAW resonators. These results offer promising perspectives towards the development of SAW and BAW filters on 8-inch POI substrates