Structural, morphological and acoustic properties of AlN thick films sputtered on Si(001) and Si(111) substrates at low temperature

• Published in: Thin solid films 2003-09, Vol.441 (1), p.32-37
• Main Authors: Caliendo, C, Imperatori, P, Cianci, E
• Format: Article
• Language: English
• Subjects: Acoustoelectric effects and surface acoustic waves (saw) in piezoelectrics; Aluminum nitride; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Piezoelectric effects; Piezoelectricity and electromechanical effects; Sputtering; X-ray diffraction
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(03)00911-8

Polycrystalline AlN thick films were deposited on Si(001) and Si(111) substrates by reactive radio frequency sputtering technique at low temperature. The structure and the morphology of the films were investigated by X-ray diffraction, scanning electron microscopy and atomic force microscopy techniques. These measurements showed that the AlN films were highly c-axis oriented, with low surface roughness. The surface acoustic wave (SAW) properties of the films were investigated: a mean value of 3.8×10 −12 C/N was estimated for the piezoelectric strain constant d 33; the phase velocities of SAWs propagating in polycrystalline AlN/(001)[110]Si and AlN/(111)[1–10]Si structures, for different film thicknesses, were calculated and found to be in good agreement with the theoretical velocities evaluated for SAWs propagating in single crystal AlN/Si structures.