Method of fabricating an acoustic resonator comprising a filled recessed region

• US 8,230,562 B2
• Filed: 11/09/2007
• Issued: 07/31/2012
• Est. Priority Date: 04/06/2005
• 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: Fazzio, Ronald S., Ruby, Richard C.
• Primary Examiner(s): Tugbang, A. Dexter
• Application Number:
  US11/938,078
• Publication Number:
  US 20080060181A1
• Time in Patent Office: 1,726 Days
• Field of Search: 295/94, 29/253.5, 298/46, 298/47, 216/41, 216/42, 310/312, 310/363, 310/364, 333/187, 333/189, 427/97.3, 427/98.4, 427/282
• 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

A method for fabricating an acoustic resonator comprises 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 forming a recessed region in the second electrode; and filling the recessed region with a fill material.

Claims

1. 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 over at least a portion of the first photo mask to form the second electrode up to a second thickness;

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

filling the recessed region with a fill material.

2. The method of claim 1, further including depositing a second photo mask over the second electrode before filling the recessed region.

3. The method of claim 1 further including forming a depression in the substrate.

4. The method of claim 1 further including filling the recessed region with a different material than the electrode material.

5. The method of claim 1, wherein filling the recessed region includes filling with a material selected from the group consisting of:

dielectrics, metals, metal alloys, piezoelectrics, Mo, Pt, Al, Cu, W, Au, Ag, polyimide, BCB, SiO₂, Si₃N₄, AN, ZnO, LiNbO₃, PZT, LiTaO₃, and Al₂O₃.