AlN/ZnO/diamond structure combining isolated and surface acoustic waves

Abstract

International audienceIn order to generate surface acoustic waves (SAW) and waveguiding layer acoustic waves (WLAW) simultaneously, a multilayer structure of AlN/ZnO/diamond has been proposed. This structure has been investigated theoretically (two-dimensional finite element method) and experimentally. The nature of the excited modes and their order were identified by modeling and confirmed experimentally by measuring the frequency response of the device in the air and in contact with the liquid. The demonstrated structure can be used to realize a packageless sensor or resonator, using the WLAW alone. A temperature compensated gas or liquid sensor can also be realized by combined usage of the SAW and the WLAW

Periodically Poled Acoustic Wave-Guide and Transducers for Radio-Frequency Applications

“…It was pointed out first theoretically and afterward experimentally that a wave could propagate without any acoustic losses and decreases exponentially in such a structure (definition of a guided mode). This description is close to the one of interface waves (Kando et al, 2006) and fairly coincides with the behavior of isolated wave (Elmazria et al, 2009). In the proposed approach however, two metal-metal bonding are required and naturally provide the excitation electrodes, yielding a significant simplification of the device fabrication compared to classical IDT-based devices.…”

“…Among all the tested devices, one can mention thick passivation SiO 2 -based structures using high velocity modes on lithium niobate (LiNbO 3 ) or lithium tantalate (LiTaO 3 ) (Kando et al, 2006), (Gachon et al 2010), yielding the definition of interface or isolated-wave-based devices but modes excited on compound substrates (Elmazria et al, 2009), for instance consisting of a piezoelectric layer (AlN, ZnO, single crystal LiNbO 3 or LiTaO 3 , etc.) deposited atop a high acoustic wave velocity material such as diamond-C, silicon carbide, sapphire, silicon, and so on (Higaki et al, 1997), (Iriarte et al, 2003), (Salut & al, 2010).…”

Theoretical investigation of surface acoustic wave propagation characteristics in periodic (AlN/ZnO)N /diamond multilayer structures

“…As alternative, AlN/ZnO/diamond 10,11 and ZnO/AlN/diamond 7,12-14 layered structures are proposed to combine the advantage of the both piezoelectric films: high K 2 of ZnO, high V p of AlN, and different TCFs. Furthermore, ZnO and AlN exhibit the same of hexagonal close-packed crystal structure and the relatively small lattice mismatch, [15][16][17][18] which is benefit to grow high quality AlN film on ZnO and vice versa.…”

AlN, ZnO thin films and AlN/ZnO or ZnO/AlN multilayer structures deposited by PLD for surface acoustic wave applications

“…Multilayered structures like AlN/ZnO/Al 2 O 3 (C) allow an acoustic confinement of the wave in a low acoustic velocity layer between two high acoustic velocity layers [10] and would limit the chemical modification of surfaces (oxidation, humidity…). The development of these multilayers would also be an alternative to the use of diamond (high acoustic wave velocity % 18000 m s…”