ZnO/AlN/diamond layered structure for SAW devices combining high velocity and high electromechanical coupling coefficient

Abstract

Authorship statement : the submission of the manuscript has been approved buy all coauthors Prime Novelty:In this work we propose a new Surface acoustic wave structure (ZnO/AlN/diamond) leading to perform SAW devices combining high acoustic velocity and high electromechanical coupling coefficient. Theoretical as well as experimental results demonstrate the potentiality of this new structure.

Structural and electrical properties of ZnO films on freestanding thick diamond films

“…Recently, much attention has been paid to high quality piezoelectric ZnO films for SAW devices with operation frequencies higher than 1 GHz, whereas even greater frequencies (superior to 2.5 GHz) tend to push the limits of conventional photolithography [8] . The use of ZnO based on diamond as SAW substrates [8][9][10][11][12][13][14] offers an attractive means for relaxation of the lithographic criteria since diamond has the highest stiff coefficient and sound velocity. SAW devices have been reported based on ZnO/ diamond/Si layered structures with a diamond layer of 10-100 μm deposited by chemical vapour deposition (CVD) technique [9][10][11][12][13][14] .…”

Diamond in Surface Acoustic Wave Sensors

“…In the calculations, the following values are used: the wave velocity in silicon v Si = 4900 m/s, and the density of silicon ρ Si = 2.329 g/cm 3 . Figure 3 shows that the wave velocity of an AlN/diamond structure is greater than the velocity in a single AlN layer (v AlN = 5600 m/s, [6]), or AlN/Si structure. The increase of the wave velocity enables higher operating frequencies without submicron electrode manufacturing and higher sensor sensitivities.…”

“…In the same figure, the corresponding function for ST quartz is presented ( points). According to (6), AlN/diamond based sensors have approximately 2.3 times better mass sensitivity than quartz-based sensors for the same wavelength (5). Relative frequency changes versus gas concentrations of ethanol and CO sensor are calculated using (5) and presented in Fig.…”

“…Recently, multilayered substrates are used for the wave velocity increase [4]. The highest velocities are achieved when the piezoelectric material is placed on the top of the diamond layer, due to its highest acoustic wave velocity (10750 m/s) [5][6][7][8][9][10][11][12][13]. Several piezoelectric materials [5] in combination with diamond/silicon substrates have been investigated theoretically and experimentally.…”

Analysis and Modeling of Surface Acoustic Wave Chemical Vapor Sensors

“…Recently, multilayered substrates are used for the wave velocity increase [Ahmadi et al, 2004]. The highest velocities are achieved when the piezoelectric material is placed on the top of the diamond layer, due to its highest acoustic wave velocity [Assouar et al, 2000;Benetti et al, 2004;Benetti et al, 2005;Besmaine et al, 2008;Hakiki et al, 2005;Mortet et al, 2008;Jian et al, 2008;Shikata et al, 2005]. Several piezoelectric materials in combination with diamond/silicon substrates have been investigated theoretically and experimentally.…”