In situ high-temperature characterization of AlN-based surface acoustic wave devices

Abstract

International audienc

First investigations on stoichiometric lithium niobate as piezoelectric substrate for high-temperature surface acoustic waves applications

“…Other notable performances have been obtained with AlN/Sapphire bilayer structure. AlN suffers from steady oxidation above 700°C in air [9], but can be operated up to at least 1000°C under low-O environments [10] or in air if protected by an overlayer [11].…”

Theoretical and experimental study of ScAlN/Sapphire structure based SAW sensor

“…Moreover, AlN is chemically inert and shows a high temperature stability. Indeed it is an intrinsically-poled, nonferroelectric material (no Curie point) which has been reported to retain its piezoelectric properties at temperatures above 1000°C [3]. However, the low electromechanical coupling coefficient (K 2 ) and piezoelectric constant (d 33 ) of AlN thin compared to PZT and ZnO thin films, limits its wide applications in sensors, wide band filters, and MEMS including for energy harvesting.…”

Notice of Removal: Comparison between Ir, Ir0.85Rh0.15 and Ir0.7 Rh0.3 thin films as electrodes for surface acoustic waves applications above 800 °C in air atmosphere

“…In this context, iridium, whose melting point is as high as 2440°C, is an appropriate candidate. Indeed, pure Ir electrodes show a far better resistance to agglomeration phenomena than Pt electrodes under vacuum conditions [5,9]. The use of Ir electrodes is more problematic under air atmosphere as Ir oxidizes in IrO 2 in the vicinity of 800°C.…”