SAW Resonators and Filters Based on Sc0.43Al0.57N on Single Crystal and Polycrystalline Diamond

Abstract

The massive data transfer rates of nowadays mobile communication technologies demand devices not only with outstanding electric performances but with example stability in a wide range of conditions. Surface acoustic wave (SAW) devices provide a high Q-factor and properties inherent to the employed materials: thermal and chemical stability or low propagation losses. SAW resonators and filters based on synthetized by reactive magnetron sputtering on single crystal and polycrystalline diamond substrates were fabricated and evaluated. Our SAW resonators showed high electromechanical coupling coefficients for Rayleigh and Sezawa modes, propagating at 1.2 GHz and 2.3 GHz, respectively. Finally, SAW filters were fabricated on /diamond heterostructures, with working frequencies above 4.7 GHz and ~200 MHz bandwidths, confirming that these devices are promising candidates in developing 5G technology.

Zeta potential and nanodiamond self assembly assisted diamond growth on lithium niobate and lithium tantalate single crystal

“…The first is to put the diamond on the piezo material either by direct growth [6,7] or by direct bonding [8,9,10,11,12] and the second, is grow the piezo electric material on top of polished diamond [13,14]. The growth of piezo material on diamond leads formation of polycrystalline piezo material which has been shown to effect device performance when compared with single crystal material [14]. Furthermore, the current state-of-the-art for direct bonding is limited to single crystal diamond.…”

High electro-mechanical coupling coefficient SAW device with ScAlN on diamond

“…28,29) It was reported that the highest piezoelectricity appeared when the Sc concentration was 43%. Since then, many studies have been conducted on ScAlN-based SAW devices [30][31][32][33][34][35][36][37] including temperature coefficient measurement 35) and ladder type filter fabrication. 36) In this study, we investigated ScAlN/AlN/diamond structure SAW devices by higher Sc concentration films to realize a higher K 2 material system.…”

Editorial for Special Issue “Piezoelectric Aluminium Scandium Nitride (AlScN) Thin Films: Material Development and Applications in Microdevices”

“…In the last section, six papers address the fabrication and performance of various AlScN-based devices [ 12 , 13 , 14 , 15 , 16 , 17 ]. It has been recognized quite early in the development of AlScN that the etching rate drops dramatically compared to pure AlN, and the existing etching approaches used for group-III nitrides must be revised, especially when vertical side-wall geometry has to be well controlled.…”

“…A 10-fold increase in the deflection per electric field in AlScN micromirrors was observed compared to AlN, showing the high potential of such MOEMS for future micro-optics applications with large static scan angles. The paper by Lozano et al [ 16 ] focuses on AlScN-on-diamond surface acoustic wave (SAW) resonators and filters. Single crystal and polycrystalline diamond were compared, and in both types of resonators, Rayleigh and Sezawa modes were excited.…”