Electronic device on substrate with cavity and mitigated parasitic leakage path

• US 8,080,854 B2
• Filed: 12/22/2008
• Issued: 12/20/2011
• Est. Priority Date: 03/10/2006
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Fazzio, R. Shane, Ruby, Richard C., Wade, Christopher P., Frank, Michael Louis, Feld, David A.
• Primary Examiner(s): Tran, Tan N
• Application Number:
  US12/341,122
• Publication Number:
  US 20090101999A1
• Time in Patent Office: 1,093 Days
• Field of Search: 257/187, 257/245, 257/311, 257/324, 257/348, 257/416, 333/187, 310/348, 310/311, 310/324
• US Class Current: 257/416
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence
• CPC Class Codes: H03H 9/02118 of lateral leakage between adjacent resonators
• CPC Class Codes: H03H 9/02125 of parasitic elements
• CPC Class Codes: H03H 9/172 Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume

Abstract

An electronic device. The electronic device includes a first electrode and a coating layer. The electronic device is fabricated on a substrate; the substrate has a cavity created in a top surface of the substrate; and the first electrode is electrically coupled to the substrate. The coating layer coats at least part of a substrate surface in the cavity, and the presence of the coating layer results in a mitigation of at least one parasitic leakage path between the first electrode and an additional electrode fabricated on the substrate.

Claims

1. An electronic device, comprising:

a substrate;

a cavity disposed in the substrate;

a film bulk acoustic resonator disposed over the cavity and comprising;

a first electrode disposed over the cavity;

a piezoelectric layer disposed over the first electrode; and

a second electrode disposed over the piezoelectric layer; and

a coating layer disposed in the cavity and electrically connected to a contact that is not an electrode of the electronic device.

2. The electronic device as recited in claim 1, wherein the electronic device is selected from the group consisting of radio-frequency filters and resonators.

3. The electronic device as recited in claim 1, wherein the coating layer material is selected from the group of materials consisting of a dielectric material, a semiconductor material, a conductive material, a metal, a ceramic, an implanted material, silicon dioxide, silicon nitride, aluminum nitride, molybdenum, and gold.

4. The electronic device as recited in claim 1, wherein the coating layer is attachable to a fixed electrical potential.

5. The electronic device as recited in claim 1, wherein the substrate is selected from the group consisting on a semiconductor, a semiconductor wafer, silicon, a silicon wafer, and a ceramic substrate.

6. The electronic device as recited in claim 1, wherein the coating layer further overlies at least a part of the top surface of the substrate.

7. The electronic device as recited in claim 1, wherein the coating layer comprises multiple layers.

8. An electronic device as claimed in claim 1, wherein the contact is a ground contact.