Film bulk acoustic resonator package and method of fabricating same

• US 20060012021A1
• Filed: 07/13/2004
• Published: 01/19/2006
• Est. Priority Date: 07/13/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies Wireless IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Matta, Farid, Bai, Qing, Verhoeven, Tracy, Larson,, John D. III
• Granted Patent: US 7,615,833 B2
• Time in Patent Office: Days
• US Class Current: 257/686
• CPC Class Codes: H03B 5/326 the resonator being an acoustic wave device, e.g. SAW or BAW device
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence
• CPC Class Codes: H03H 9/0547 consisting of a vertical arrangement H03H9/0566 takes precedence
• CPC Class Codes: H03H 9/105 the enclosure being defined by a cover cap mounted on an element forming part of the BAW device
• CPC Class Codes: H03H 9/706 Duplexers

Abstract

A microfabricated device has a first substrate, a second substrate, a film bulk acoustic resonator (FBAR) device, and a circuit. The second substrate is bonded to the first substrate to define a chamber. The FBAR device is located on a surface of the first substrate and inside the chamber. The circuit is located on a surface of the second substrate and inside the chamber. An electrical connection connects the circuit and the FBAR device.

Claims

1. A microfabricated device, comprising:

a first substrate;

a second substrate bonded to said first substrate to define a chamber;

a film bulk acoustic resonator (FBAR) device located on a surface of said first substrate inside said chamber;

a circuit located on a surface of said second substrate inside said chamber; and

an electrical connection between said circuit and said FBAR device.

2. The device of claim 1, further comprising a hermetic gasket between said first and second substrates, said gasket defining part of said chamber.

3. The device of claim 1, wherein said electrical connection connects a signal between said FBAR device and said circuit, and said circuit is configured to process said signal.

4. The device of claim 1, wherein:

said circuit is configured to process a signal, and

said electrical connection connects said signal from said circuit to said FBAR device.

5. The device of claim 1, wherein said device constitutes part of a cellular telephone, said cellular telephone comprising an antenna electrically connected to said FBAR device.

6. The device of claim 5, wherein said circuit comprises a power amplifier.

7. The device of claim 1, further comprising:

an electrically conductive via extending through said first substrate; and

an electrical connection between said via and said FBAR device.

8. The device of claim 7, further comprising:

an electrically conductive via extending through said second substrate; and

an electrical connection between said circuit and said via extending through said second substrate.

9. The device of claim 1, wherein said second substrate has a thickness of less than approximately 150 micrometers.

10. The device of claim 1, wherein said first and second substrates comprise silicon.

11. The device of claim 1, wherein said second substrate comprises gallium arsenide.

12. The device of claim 11, wherein said first substrate comprises alumina.

13. The device of claim 1, wherein said FBAR device comprises a tunable FBAR circuit, said circuit comprising a voltage-variable capacitor electrically connected to an FBAR.

14. The device of claim 13, wherein said circuit located on said surface of said second substrate comprises an operational amplifier, and wherein said tunable FBAR circuit is positioned within a feedback path of said operational amplifier.

15. A method for manufacturing a microfabricated device, the method comprising:

providing first and second substrates;

forming a film bulk acoustic resonator (FBAR) device on a surface of said first substrate;

forming a circuit on a surface of said second substrate; and

bonding said first and second substrates together to define a chamber in which said FBAR device and said circuit are located;

said bonding establishing an electrical connection between said FBAR device and said circuit.

16. The method of claim 15, further comprising forming a hermetic gasket between said first and second substrates, said hermetic gasket defining part of said chamber.

17. The method of claim 15, further comprising:

providing a cellular telephone, said cellular telephone comprising an antenna; and

electrically connecting said FBAR device to said antenna.

18. The method of claim 17, wherein said circuit comprises a power amplifier.

19. The method of claim 15, further comprising:

forming an electrically conductive via extending through said first substrate; and

establishing an electrical connection between said via and said FBAR device.

20. The method of claim 19, further comprising:

forming an electrically conductive via extending through said second substrate; and

establishing an electrical connection between said circuit and said via extending through said second substrate.

21. The method of claim 15, further comprising thinning said second substrate.

22. The method of claim 21, wherein said thinning comprises thinning said second substrate to a thickness less than approximately 150 micrometers.

23. The method of claim 15, wherein said second substrate comprises gallium arsenide.

24. The method of claim 23, wherein said first substrate comprises alumina.

25. The method of claim 15, wherein said FBAR device comprises a tunable FBAR circuit, said circuit comprising a voltage-variable capacitor electrically connected to an FBAR.

26. The method of claim 25, wherein said circuit formed on said surface of said second substrate comprises an operational amplifier, and wherein said tunable FBAR circuit is positioned within a feedback path of said operational amplifier.