Multi-band filter module and electronic device comprising the same

• US 9,628,048 B2
• Filed: 07/09/2014
• Issued: 04/18/2017
• Est. Priority Date: 07/27/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Nam, Kuang-woo, Song, In-sang, Kim, Chul-soo, Park, Yun-kwon, Park, Eun-seok
• Primary Examiner(s): Summons, Barbara
• Application Number:
  US14/327,151
• Publication Number:
  US 20140312993A1
• Time in Patent Office: 1,014 Days
• Field of Search: 333133
• CPC Class Codes: H03H 2003/0071 of bulk acoustic wave and surface acoustic wave elements in the same process
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence
• CPC Class Codes: H03H 3/08 for the manufacture of resonators or networks using surface acoustic waves
• 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 9/1092 the enclosure being defined by a cover cap mounted on an element forming part of the surface acoustic wave [SAW] device on the side of the IDT's
• CPC Class Codes: H03H 9/46 Filters multiple-port electromechanical filters H03H9/70
• CPC Class Codes: H03H 9/54 comprising resonators of piezoelectric or electrostrictive material H03H9/64 takes precedence
• CPC Class Codes: H03H 9/64 using surface acoustic waves
• CPC Class Codes: H03H 9/703 Networks using bulk acoustic wave devices
• CPC Class Codes: H03H 9/706 Duplexers
• CPC Class Codes: H03H 9/72 Networks using surface acoustic waves
• CPC Class Codes: H03H 9/725 Duplexers
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

A method of fabricating a multi-band filter module is provided. The method includes forming a Film Bulk Acoustic Resonator (FBAR) on a piezoelectric substrate by forming a resonant part on the piezoelectric substrate and then an air gap recessed on a surface of the piezoelectric substrate and positioned under the resonant part; and forming a Surface Acoustic Wave (SAW) device on the piezoelectric substrate in which the steps of forming the FBAR and the SAW are concurrently performed.

Claims

1. A multi-band filter module comprising:

a substrate;

a first filter to operate in a first frequency band and including a resonant part electrically coupled with the substrate and an air gap formed between the resonant part and the substrate, and the resonant part including a first electrode, a second electrode, and a piezoelectric film formed between the first and second electrodes, wherein the first electrode covers a portion of the air gap, and the piezoelectric film covers a portion of the first electrode and the remaining portion of the air gap; and

a second filter to operate in a second frequency band lower than the first frequency band,

wherein the substrate comprises a piezoelectric substrate.

2. The multi-band filter module of claim 1, wherein the first filter is formed on the substrate, and the second filter is formed on the substrate and spaced apart from the first filter.

3. The multi-band filter module of claim 1, wherein the second filter comprises a surface acoustic wave (SAW) filter.

4. The multi-band filter module of claim 1, wherein the first electrode or the second electrode comprises, as a conductive substance, at least one of aluminium (Al), tungsten (W), gold (Au), platinum (Pt), nickel (Ni), titanium (Ti), chrome (Cr), palladium (Pd), or molybdenum (Mo).

5. The multi-band filter module of claim 1, wherein the piezoelectric film comprises, as a piezoelectric substance, at least one of aluminium nitride (AlN) or zinc oxide (ZnO).

6. The multi-band filter module of claim 1, wherein the air gap is formed to have a specified depth extending downwardly from an upper surface of the substrate.

7. The multi-band filter module of claim 1, wherein the first filter comprises a film bulk acoustic resonator (FBAR) filter.

8. A multi-band filter module comprising:

a substrate;

a first filter formed above the substrate, the first filter to operate in a first frequency band and including a resonant part located above an air gap formed in or above the substrate, the resonant part electrically coupled with the substrate and including a first electrode, a second electrode, and a piezoelectric film formed between the first and second electrodes, wherein the first electrode covers a portion of the air gap, and the piezoelectric film covers a portion of the first electrode and the remaining portion of the air gap; and

a second filter formed above the substrate, the second filter to operate in a second frequency band,

wherein the substrate comprises a piezoelectric substrate.

9. The multi-band filter module of claim 8, wherein the second filter comprises a surface acoustic wave (SAW) filter.

10. The multi-band filter module of claim 8, wherein the second filter is to operate in a lower frequency band than the first frequency band.

11. The multi-band filter module of claim 8, wherein the first electrode or the second electrode comprises, as a conductive substance, at least one of aluminium (Al), tungsten (W), gold (Au), platinum (Pt), nickel (Ni), titanium (Ti), chrome (Cr), palladium (Pd), or molybdenum (Mo).

12. The multi-band filter module of claim 8, wherein the piezoelectric film comprises, as a piezoelectric substance, at least one of aluminium nitride (AlN) or zinc oxide (ZnO).

13. The multi-band filter module of claim 8, wherein the air gap is formed to have a specified depth extending downwardly from an upper surface of the substrate.

14. An electronic device comprising:

a multi-band filter module including;

a substrate;

a film bulk acoustic resonator (FBAR) filter formed above the substrate, the FBAR filter to operate in a first frequency band; and

a second filter formed above the substrate, the second filter to operate in a second frequency band,

wherein the FBAR filter comprises a resonant part located above an air gap formed in or above the substrate, the resonant part being electrically coupled with the substrate,

wherein the resonant part comprises a first electrode, a second electrode, and a piezoelectric film formed between the first and second electrodes, and

wherein the first electrode covers a portion of the air gap, and the piezoelectric film covers a portion of the first electrode and the remaining portion of the air gap, and

wherein the substrate comprises a piezoelectric substrate.

15. The electronic device of claim 14, wherein the second filter comprises a surface acoustic wave (SAW) filter.

16. The electronic device of claim 14, wherein the second filter is to operate in a second frequency band lower than the first frequency band.

17. The electronic device of claim 14, wherein the air gap is formed to have a specified depth extending downwardly from an upper surface of the substrate.