Acoustic resonator device with air-ring and temperature compensating layer

摘要

A bulk acoustic wave (BAW) resonator device includes a substrate defining a cavity, a bottom electrode formed over the substrate and at least a portion of the cavity, a piezoelectric layer formed on the bottom electrode, and a top electrode formed on the piezoelectric layer. An air-wing and an air-bridge are formed between the piezoelectric layer and the top electrode, the air-wing having an inner edge that defines an outer boundary of an active region of the BAW resonator device. The BAW resonator device further includes a temperature compensation feature having positive temperature coefficient for offsetting at least a portion of a negative temperature coefficient of the piezoelectric layer. The temperature compensation feature extends outside the active region by a predetermined length.

主权项

1. A bulk acoustic wave (BAW) resonator device, comprising:
a substrate; a bottom electrode formed over the substrate; a piezoelectric layer formed on the bottom electrode; a top electrode formed on the piezoelectric layer; an air-wing and an air-bridge formed between the piezoelectric layer and the top electrode, the air-wing having an inner edge that defines an outer boundary of an active region of the BAW resonator device; and a temperature compensation feature having a positive temperature coefficient for offsetting at least a portion of a negative temperature coefficient of the piezoelectric layer, the temperature compensation feature located in one of the top electrode, the piezoelectric layer or the bottom electrode, wherein the temperature compensation feature extends outside the active region by a predetermined length.