ACOUSTIC RESONATOR PERFORMANCE ENHANCEMENT USING FILLED RECESS REGION

• US 20080060181A1
• Filed: 11/09/2007
• Published: 03/13/2008
• Est. Priority Date: 04/06/2005
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Fazzio, Ronald, Ruby, Richard
• Granted Patent: US 8,230,562 B2
• Time in Patent Office: Days
• US Class Current: 29/25.35
• CPC Class Codes: H03H 9/02118 of lateral leakage between adjacent resonators
• CPC Class Codes: H03H 9/02149 of ageing changes of characteristics, e.g. electro-acousto-migration
• CPC Class Codes: H03H 9/13 for networks consisting of piezoelectric or electrostrictive materials H03H9/145 takes precedence
• CPC Class Codes: H03H 9/132 characterized by a particular shape
• CPC Class Codes: H03H 9/173 Air-gaps
• CPC Class Codes: H03H 9/175 Acoustic mirrors
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

An acoustic resonator that includes a substrate, a first electrode, a layer of piezoelectric material, a second electrode, and a fill region. The first electrode is adjacent the substrate, and the first electrode has an outer perimeter. The piezoelectric layer is adjacent the first electrode. The second electrode is adjacent the piezoelectric layer and the second electrode has an outer perimeter. The fill region is in one of the first and second electrodes.

Claims

1-23. -23. (canceled)

24. A method for fabricating an acoustic resonator comprising:

providing a substrate;

fabricating a first electrode adjacent the substrate;

fabricating a piezoelectric layer adjacent the first electrode;

depositing electrode material to form a second electrode up to a first thickness adjacent the piezoelectric layer;

depositing a first photo mask over the second electrode;

depositing additional electrode material to form the second electrode up to a second thickness;

removing the photo mask thereby revealing a recessed region in the second electrode; and

filling the recessed region with a fill material.

25. The method of claim 24, further including depositing a second photo mask over the second electrode before filling the recessed region.

26. The method of claim 24 further including forming a depression in the substrate.

27. The method of claim 24 further including filling the recessed region with a different material than the electrode material.

28. The method of claim 24, wherein filling the recessed region includes filling with a material selected from the group comprising dielectrics, metals, metal alloys, piezoelectrics, Mo, Pt, Al, Cu, W, Au, Ag, polyimide, BCB, SiO₂, Si₃N₄, AlN, ZnO, LiNbO₃, PZT, LiTaO₃, and Al₂O₃.

29. A method for fabricating an acoustic resonator comprising:

providing a substrate;

fabricating a first electrode adjacent the substrate;

fabricating a piezoelectric layer adjacent the first electrode;

depositing electrode material to form a second electrode;

depositing a first photo mask over the second electrode;

etching the second electrode to form a recessed region in the second electrode; and

filling the recessed region with a fill material.