Aluminum nitride dopant scheme for bulk acoustic wave filters
Disclosed is piezoelectric material formed of aluminum nitride (AlN) doped with one or more of zinc (Zn), silicon (Si), lithium (Li), calcium (Ca) and/or oxygen (O) and an acoustic wave resonator including same.
1. An acoustic wave resonator comprising a piezoelectric material formed of aluminum nitride (AlN) doped with one or more dopants to enhance performance of the acoustic wave resonator, the piezoelectric material having a chemical formula of one of
Al 1-2x Zn x Si x N;
Al 1-3x Li x Si 2x N; or
Ca 15 Si 18 Al 2 O 12 N 28 .
2. An acoustic wave filter including the acoustic wave resonator of claim 1 .
3. The acoustic wave filter of claim 2 comprising a bulk acoustic wave (BAW) resonator including the doped AlN.
4. The acoustic wave filter of claim 3 wherein the BAW resonator is one of a film bulk acoustic wave resonator, a Lamb wave resonator, or a solidly mounted resonator.
5. The acoustic wave filter of claim 3 comprising a radio frequency filter.
6. An electronics module including the acoustic wave filter of claim 5 .
7. An electronic device including the electronics module of claim 6 .
8. The acoustic wave resonator of claim 1 wherein the piezoelectric material has a Wurtzite crystal structure.
9. A method of forming an acoustic wave resonator comprising depositing electrodes on a film of piezoelectric material having a chemical formula of one of
Al 1-2x Zn x Si x N;
Al 1-3x Li x Si 2x N; or
Ca 15 Si 18 Al 2 O 12 N 28 .
10. The method of claim 9 wherein depositing the electrodes on the film of piezoelectric material includes depositing a first electrode on a top surface of the film of piezoelectric material and depositing a second electrode on a bottom surface of the film of piezoelectric material.
11. The method of claim 10 wherein the acoustic wave resonator is a film bulk acoustic wave resonator and the method further comprises defining a cavity below the lower surface of the film of piezoelectric material.
12. The method of claim 10 wherein the acoustic wave resonator is a Lamb wave resonator and depositing the first electrode on the top surface of the film of piezoelectric material comprises depositing interdigital transducer electrodes on the top surface of the film of piezoelectric material.
13. The method of claim 10 wherein the acoustic wave resonator is a solidly mounted resonator and the method further comprises forming the film of piezoelectric material on a top surface of a Bragg reflector.
14. A piezoelectric material comprising aluminum nitride (AlN) doped with one or more dopants, the piezoelectric material having a chemical formula of one of
Al 1-2x Zn x Si x N;
Al 1-3x Li x Si 2x N; or
Ca 15 Si 18 Al 2 O 12 N 28 .
15. The piezoelectric material of claim 14 having a Wurtzite crystal structure.