Bulk Acoustic Wave Devices with Temperature-Compensating Niobium Alloy Electrodes

摘要

A bulk acoustic wave (BAW) resonator having a first electrode, a second electrode, and a piezoelectric layer between the first electrode and the second electrode. The first electrode is of a first electrode material. The second electrode is of a second electrode material. The piezoelectric layer is of a piezoelectric material doped with at least one rare earth element. The BAW resonator has a resonant frequency dependent at least in part on respective thicknesses and materials of the first electrode, the second electrode and the piezoelectric layer. The resonant frequency has a temperature coefficient. At least one of the first electrode and the second electrode includes a niobium alloy electrode material that, relative to molybdenum as the electrode material, reduces the temperature coefficient of the resonant frequency of the BAW resonator.

主权项

1. A bulk acoustic wave (BAW) resonator, comprising:
a first electrode of a first electrode material, the first electrode having a first electrode thickness; a second electrode of a second electrode material, the second electrode having a second electrode thickness; and a piezoelectric layer between the first electrode and the second electrode, the piezoelectric layer comprising a piezoelectric material doped with at least one rare earth element, and having a piezoelectric layer thickness; in which: the BAW resonator has a resonant frequency dependent at least in part on the first electrode thickness, the first electrode material, the second electrode thickness, the second electrode material, the piezoelectric layer thickness, and the piezoelectric material, the resonant frequency having a temperature coefficient; and at least one of the first electrode material and the second electrode material is a niobium alloy that, relative to molybdenum as the respective at least one of the first electrode material and the second electrode material, reduces the temperature coefficient of the resonant frequency of the BAW resonator.