摘要:
A thin film bulk acoustic resonator (FBAR) includes a first electrode, a first piezoelectric layer having a first c-axis orientation and on the first electrode, a second piezoelectric layer having a second c-axis orientation over the first piezoelectric layer, and a second electrode on the second piezoelectric layer. The first and second piezoelectric layers are made of respective different piezoelectric materials. The FBAR can be set to have different resonance frequencies by selecting the first and second c-axis orientations to be respectively the same or different. The high and low frequency range of the FBAR can thus be extended.
摘要:
A method of forming an acoustic resonator includes forming a seed layer on a first electrode layer, forming a piezoelectric layer directly on a surface of the seed layer, and forming a second electrode layer on the piezoelectric layer. The piezoelectric layer includes multiple crystals of piezoelectric material, and the seed layer causes crystal axis orientations of the crystals to be substantially perpendicular to the surface of the seed layer.
摘要:
A device comprises a substrate, an acoustic stack, and a distributed Bragg reflector. The acoustic stack comprises a first electrode formed on the substrate, a first piezoelectric layer formed on the first electrode, a second electrode formed on the first piezoelectric layer, a second piezoelectric layer formed on the second electrode, and a third electrode formed on the second piezoelectric layer. The distributed Bragg reflector is formed adjacent to the acoustic stack and provides it with acoustic isolation.
摘要:
In a representative embodiment, a bulk acoustic wave (BAW) resonator, comprises: a first electrode disposed over a substrate; a first piezoelectric layer disposed over the first electrode, the first piezoelectric layer having a first c-axis oriented along a first direction; a second electrode disposed over the first piezoelectric layer; and a second piezoelectric layer disposed over the first electrode and adjacent to the first piezoelectric layer, wherein the second piezoelectric layer has a second c-axis oriented in a second direction that is substantially antiparallel to the first direction.