title: Ultrafast optical technique for measuring the electrical dependence of the elasticity of piezoelectric thin film: demonstration on AlN.
abstract: We present a technique based on ultrafast acoustics which permits us to measure the electrical dependence of the elastic properties of a thin piezoelectric layer. Ultrafast acoustics offers a unique way of measuring elastic properties of thin-layer in a non-destructive way using ultrashort optical pulses. We apply this technique to a thin layer to which a dc voltage is simultaneously applied. Both the film thickness and the sound velocity are affected. The two effects can be separated by use of a semi-transparent top electrode. A demonstration is made on a thin aluminum nitride (AlN). From that the d(33) piezoelectric coefficient and the stiffness variation induced by the bias in AlN are measured.
authors: Institut d'Électronique, de Microélectronique et de Nanotechnologie, Unité Mixte de Recherche CNRS 8250, Avenue Poincaré BP 69, F-59652 Villeneuve d'Ascq Cedex, France. arnaud.devos@isen.fr
authors: A
authors: A
authors: Devos
authors: P
authors: P
authors: Emery
authors: E
authors: E
authors: Defay
authors: N
authors: N
authors: Ben Hassine
authors: G
authors: G
authors: Parat