The invention provides a high-frequency
acoustic wave resonator and a preparation method thereof. The high-frequency
acoustic wave resonator comprises a high-acoustic-velocity support substrate, an insulating
dielectric layer which is located on the upper surface of the high-sound-velocity supporting substrate, a piezoelectric film which is located on the upper surface of the insulating dielectriclayer, and an interdigital
electrode which is located on the upper surface of the piezoelectric film. By arranging the high-sound-velocity supporting substrate below the piezoelectric film, the soundvelocity of target elastic
waves excited and propagated in the piezoelectric film can be increased, propagation of the target elastic
waves can be effectively restrained, and the resonant frequency of the high-
frequency sound wave
resonator is improved; the insulating
dielectric layer is arranged between the piezoelectric film and the high-sound-velocity supporting substrate, the leakage of
electric field energy in the piezoelectric film can be effectively reduced, and the
electromechanical coupling coefficient of the high-
frequency sound wave resonator can be enhanced; by selecting the appropriate insulating
dielectric layer, temperature compensation can be carried out on the high-frequency
acoustic wave resonator, temperature drift of the high-frequency acoustic wave resonator is reduced, and temperature stability of the high-frequency acoustic wave resonator is improved.