Patent ID: 8830012

Claim:
An acoustic wave resonator comprising: (a) a substrate defining an air cavity; (b) a first pair of low and high impedance layers formed on the substrate and located over the air cavity; (c) a seed layer formed on the first pair of low and high impedance layers; (d) a first electrode formed on the seed layer; (e) a piezoelectric layer formed on the first electrode; (f) a second electrode formed on the piezoelectric layer; (g) a second pair of low and high impedance layers formed on the second electrode; and (h) a passivation layer formed on the second pair of low and high impedance layers, wherein the first pair of low and high impedance layers comprises a first high impedance layer formed over the air cavity, and a first low impedance layer formed between the first high impedance layer and the seed layer; wherein the second pair of low and high impedance layers comprises a second low impedance layer formed on the second electrode, and a second high impedance layer formed between the second low impedance layer and the passivation layer; wherein each of the first and second low impedance layers is formed of a first material having an acoustic impedance lower than about 20 Mrayl; and wherein each of the first and second high impedance layers is formed of a second material having acoustic impedance higher than about 40 Mrayl.