Correlation Between the Resonator Properties and Fourier Transform Infrared Spectra of Silicon Oxynitride Films for Surface Acoustic Wave Devices

In this paper, we discuss the temperature coefficient of frequency (TCF) and Q factor in the structure of SiO
_x
N
_y
/ LiTaO
₃
. We studied the relationship of the TCF and Q factor with the optical properties of the SiO
_x
N
_y
films measured by Fourier transform infrared spectroscopy (FT-IR). We found that the Q factor of the device increased while TCF was decreased as the Si-O bond angle decreased in SiOxNy film. These results indicate that the Si-O atomic structure measured by FT-IR governs the device properties even when the N dopant is added.