Acoustic resonator structure with inclined C-axis piezoelectric bulk and crystalline seed layers

Patent metadata

Field	Value
Publication number	US-10574204-B2
Application number	US-201615293082-A
Country	US
Kind code	B2
Filing date	Oct 13, 2016
Priority date	Oct 14, 2015
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

Systems and methods for growing hexagonal crystal structure piezoelectric material with a c-axis that is tilted (e.g., 25 to 50 degrees) relative to normal of a face of a substrate are provided. A deposition system includes a linear sputtering apparatus, a translatable multi-aperture collimator, and a translatable substrate table arranged to hold multiple substrates, with the substrate table and/or the collimator being electrically biased to a nonzero potential. An enclosure includes first and second deposition stations each including a linear sputtering apparatus, a collimator, and a deposition aperture.

First claim

What is claimed is:

1. An acoustic resonator structure comprising:
a substrate;
at least one first electrode structure supported by the substrate;
a crystalline seed layer arranged over the substrate and the at least one first electrode structure;
a hexagonal crystal structure piezoelectric material bulk layer arranged over the crystalline seed layer, the bulk layer covering an area of the substrate; and
at least one second electrode structure arranged over at least a portion of the hexagonal crystal structure piezoelectric material bulk layer;
wherein at least 75% of the hexagonal crystal structure piezoelectric material bulk layer comprises a c-axis having an orientation distribution in a range of from 25 degrees to 50 degrees relative to normal of a face of the substrate, and wherein the c-axis orientation distribution is substantially uniform over the area covered by the bulk layer.

2. The acoustic resonator structure of claim 1 , wherein the crystalline seed layer is compositionally matched to the hexagonal crystal structure piezoelectric material bulk layer.

3. The acoustic resonator structure of claim 1 , wherein a thickness of the crystalline seed layer is no greater than about 20% of a combined thickness of the hexagonal crystal structure piezoelectric material bulk layer and the crystalline seed layer.

4. The acoustic resonator structure of claim 1 , wherein the crystalline seed layer comprises a thickness in a range of from about 500 Angstroms to about 2,000 Angstroms.

5. The acoustic resonator structure of claim 1 , wherein at least 50% of the crystalline seed layer comprises a c-axis having an orientation distribution predominantly in a range of from 0 degrees to 35 degrees relative to normal of a face of the substrate.

6. The acoustic resonator structure of claim 1 , wherein the hexagonal crystal structure piezoelectric material bulk layer comprises a thickness in a range of from about 4,000 Angstroms to about 26,000 Angstroms.

7. The acoustic resonator structure of claim 1 , wherein the substrate comprises a semiconductor material.

8. The acoustic resonator structure of claim 1 , further comprising an acoustic reflector structure arranged between the substrate and the at least one first electrode structure.

9. The acoustic resonator structure of claim 8 , wherein the substrate is arranged between a backside surface and the acoustic reflector structure, and the backside surface comprises a roughened surface configured to reduce or eliminate backside acoustic reflection.

10. The acoustic resonator structure of claim 1 , wherein the substrate defines a recess, a support layer is arranged over the recess, and the support layer is arranged between the substrate and at least a portion of the at least one first electrode structure.

11. The acoustic resonator structure of claim 1 , wherein at least 90% of the hexagonal crystal structure piezoelectric material bulk layer comprises a c-axis having an orientation distribution in a range of from 25 degrees to 50 degrees relative to normal of a face of the substrate.

12. The acoustic resonator structure of claim 1 , wherein at least 75% of the hexagonal crystal structure piezoelectric material bulk layer comprises a c-axis having an orientation distribution in a range of from 30 degrees to 40 degrees relative to normal of a face of the substrate.

13. The acoustic resonator structure of claim 1 , wherein less than about 3 percent of the c-axis orientation distribution of the hexagonal crystal structure piezoelectric material bulk layer is in a range of from 0 degrees to 15 degrees relative to normal of a face of the substrate.

14. The acoustic resonator structure of claim 1 , wherein the substrate comprises a diameter of at least about 50 mm, and the hexagonal crystal structure piezoelectric material bulk layer covers at least about 50% of a face of the substrate.

15. The acoustic resonator structure of claim 1 , wherein the substrate comprises a diameter of at least about 100 mm, and the hexagonal crystal structure piezoelectric material bulk layer covers at least about 50% of a face of the substrate.

16. The acoustic resonator structure of claim 1 , wherein the hexagonal crystal structure piezoelectric material bulk layer comprises aluminum nitride or zinc oxide.

17. An acoustic resonator structure comprising:
a substrate;
at least one first electrode structure supported by the substrate;
a crystalline seed layer arranged over the substrate and the at least one first electrode structure;
a hexagonal crystal structure piezoelectric material bulk layer arranged over the crystalline seed layer; and
at least one second electrode structure arranged over at least a portion of the hexagonal crystal structure piezoelectric material bulk layer;
wherein at least 50% of the hexagonal crystal structure piezoelectric material bulk layer comprises a c-axis having an orientation distribution in a range of from 25 degrees to 50 degrees relative to normal of a face of the substrate,
wherein:
the at least one first electrode structure comprises a plurality of first electrode structures;
the at least one second electrode structure comprises a plurality of second electrode structures;
a first portion of the acoustic resonator structure comprises a first bulk acoustic wave resonator device including a first active region arranged between one first electrode structure of the plurality of first electrode structures and one second electrode structure of the plurality of second electrode structures; and
a second portion of the acoustic resonator structure comprises a second bulk acoustic wave resonator device including a second active region arranged between another first electrode structure of the plurality of first electrode structures and another second electrode structure of the plurality of second electrode structures.

18. A bulk acoustic wave resonator chip derived from the acoustic resonator structure of claim 17 .

19. A sensor or microfluidic device incorporating the bulk acoustic wave resonator chip of claim 18 .

20. An acoustic resonator structure comprising:
a substrate;
at least one first electrode structure supported by the substrate;
a crystalline seed layer arranged over the substrate and the at least one first electrode structure;
a hexagonal crystal structure piezoelectric material bulk layer arranged over the crystalline seed layer, the bulk layer having been applied using a deposition system comprising a translatable substrate table and a translatable collimator; and
at least one second electrode structure arranged over at least a portion of the hexagonal crystal structure piezoelectric material bulk layer;
wherein at least 50% of the hexagonal crystal structure piezoelectric material bulk layer comprises a c-axis having an orientation distribution predominantly in a range of from 25 degrees to 50 degrees relative to normal of a face of the substrate.

Assignees

• Qorvo Us Inc
• Qorvo Biotechnologies Llc

Inventors

• Mccarron Kevin
• Belsick John

Classifications

• C23C14/226

  in order to form films with columnar structure · CPC title

• H03H9/205

  having multiple resonators (crystal tuning forks H03H9/21) · CPC title

• H03H9/02047

  Treatment of substrates · CPC title

• C23C14/0617

  AIII BV compounds, where A is Al, Ga, In or Tl and B is N, P, As, Sb or Bi · CPC title

• C23C14/3442

  using an ion beam · CPC title