Effect of thin polyimide film on performance of AlN/SiO2/Si SAW device

The design, modeling and characterization of SAW device are presented. The attenuation rate of polyimide absorber is proportional to the length and the thickness of the absorber film. With thin polyimide films (95 nm), the wave attenuation effects of polyimide films are almost removed. Besides, the thin polyimide film seems to affect the center frequency a little, in which the center frequency is proportional to the length of thin polyimide film. So, because of the limitation of the device size, to increase the attenuation rate of the reflected wave, the thickness of the absorber film must been increased.