Acoustic characterization of AlN films using a high overtone bulk acoustic wave resonator

Abstract

Using the composite resonator with additional thick AlN film with the FWHM of rocking curve of 2.53degrees under investigation, the bulk acoustic wave attenuation constant and sound velocity along c-axis were directly measured. The method of High Overtone Bulk acoustic wave Resonator (HBAR) spectroscopy based on frequency measurements of the positions of the resonator peculiarities of phase and amplitude of electromagnetic wave reflection coefficient from composite resonator structure was applied. The method provides attenuation and velocity measurement in a wide frequency band, using the same sample. For the measurements, standard and modified HBAR spectroscopy based on the analysis of only parallel resonance properties of composite resonator structures were used.