Bulk acoustic wave device with piezoelectric layer formed by atomic layer deposition
AssigneeSkyworks Global Pte. Ltd.
InventorsStefan Bader, Kwang Jae Shin, Kezia Cheng, Alexandre Augusto Shirakawa
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Abstract
Aspects of this disclosure relate to a bulk acoustic wave device with a plurality of piezoelectric layers having at least one polarization inversion. The bulk acoustic wave device can include a first piezoelectric layer and a second piezoelectric layer over the first piezoelectric layer. The second piezoelectric layer can be formed by atomic layer deposition. The second piezoelectric layer can have an opposite polarization relative to the first piezoelectric layer. Related filters, multiplexers, packaged radio frequency modules, radio frequency front ends, wireless communication devices, and methods are disclosed.
Claims20
A bulk acoustic wave device with a plurality of piezoelectric layers with at least one polarization inversion, the bulk acoustic wave device comprising:
- a first electrode;
- a first piezoelectric layer;
- a second piezoelectric layer over the first piezoelectric layer, the second piezoelectric layer formed by atomic layer deposition, and the second piezoelectric layer having an opposite polarization relative to the first piezoelectric layer;
- a third piezoelectric layer over the second piezoelectric layer, the third piezoelectric layer formed by a method different than atomic layer deposition and having a same polarization as the second piezoelectric layer;
- and
- a second electrode positioned such that at least the first piezoelectric layer and the second piezoelectric layer are between the first electrode and the second electrode, the bulk acoustic wave device configured to generate a bulk acoustic wave.
An acoustic wave filter comprising:
- a bulk acoustic wave resonator including a first piezoelectric layer, a second piezoelectric layer over the first piezoelectric layer, and a third piezoelectric layer over the second piezoelectric layer, the second piezoelectric layer formed by atomic layer deposition, the second piezoelectric layer having an opposite polarization relative to the first piezoelectric layer, the third piezoelectric layer formed by a method different than atomic layer deposition, and the third piezoelectric layer having a same polarization as the second piezoelectric layer;
- and
- at least one additional acoustic wave resonator, the bulk acoustic wave resonator and the at least one additional acoustic wave resonator together arranged to filter a radio frequency signal.
A radio frequency front end comprising:
- an acoustic wave filter configured to filter a radio frequency signal, the acoustic wave filter including a plurality of acoustic wave resonators, the plurality of acoustic wave resonators including a bulk acoustic wave resonator, the bulk acoustic wave resonator including a first piezoelectric layer, a second piezoelectric layer over the first piezoelectric layer, and a third piezoelectric layer over the second piezoelectric layer, the second piezoelectric layer formed by atomic layer deposition, the second piezoelectric layer having an opposite polarization relative to the first piezoelectric layer, the third piezoelectric layer formed by a method different than atomic layer deposition, and the third piezoelectric layer having a same polarization as the second piezoelectric layer;
- and
- a radio frequency amplifier coupled to the acoustic wave filter.
Dependencies are inferred from the claim text.