Surface acoustic wave devices based on nanocrystalline diamond and aluminium nitride

• Published in: Diamond and related materials Vol. 13; no. 2; pp. 347 - 353
• Main Authors: Bénédic, F., Assouar, M.B., Mohasseb, F., Elmazria, O., Alnot, P., Gicquel, A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2004; Elsevier
• Subjects: Acoustoelectric effects and surface acoustic waves (saw) in piezoelectrics; Aluminium nitride; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; High frequency electronics; Materials science; Nanocrystalline diamond; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Physics; Piezoelectricity and electromechanical effects; Surface acoustic wave; Nanocrystalline diamond; High frequency electronics; Surface acoustic wave; Aluminium nitride; Atomic force microscopy; Scanning electron microscopy; Inorganic compounds; Diamonds; Roughness; Binary compounds; Acoustic surface waves; Crystal growth from vapors; XRD; Experimental study; CVD; Magnetrons; Cathode sputtering; Piezoelectric materials; Aluminium nitrides; Reactive sputtering; PECVD; Nanostructured materials; Microwave discharge; Nanocrystal
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2003.10.020

Due to its high-acoustic velocity, diamond, when combined with piezoelectric material, has a promising potentiality for high frequency surface acoustic wave (SAW) devices. In the present work, low-surface roughness nanocrystalline diamond (NCD) were deposited on silicon substrate by microwave plasma assisted chemical vapour deposition process and piezoelectric aluminium nitride films were grown by DC reactive magnetron sputtering. For the first time, SAW devices based on AlN/NCD/Silicon layered structure were successfully performed. The influence of inter-digital transducers periodicity and NCD film thickness on the acoustic velocity of the layered structure was studied. The high frequency characterisation showed that NCD presents a high-surface acoustic velocity similar to that of polycrystalline CVD diamond. Thus, taking advantage of the remarkable surface smoothness of as-grown NCD films, the polishing step of diamond substrates may be no more required prior to SAW device achievement.