Electronic component and method for manufacturing the same

• US 7,170,215 B2
• Filed: 06/10/2004
• Issued: 01/30/2007
• Est. Priority Date: 06/18/2003
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Onishi, Keiji, Namba, Akihiko, Takeda, Katsu
• Primary Examiner(s): BUDD, MARK OSBORNE
• Application Number:
  US10/865,125
• Publication Number:
  US 20040256961A1
• Time in Patent Office: 964 Days
• Field of Search: 310/324, 310330-332, 310367-369
• US Class Current: 310/324
• CPC Class Codes: B41J 2002/14266 Sheet-like thin film type piezoelectric element
• CPC Class Codes: H03H 2003/0435 of a piezoelectric layer
• CPC Class Codes: H03H 2003/0478 in a process for mass production
• CPC Class Codes: H03H 3/04 for obtaining desired frequency or temperature coefficient
• CPC Class Codes: H03H 9/173 Air-gaps
• CPC Class Codes: H03H 9/174 Membranes
• CPC Class Codes: H03H 9/175 Acoustic mirrors
• CPC Class Codes: H03H 9/564 implemented with thin-film techniques
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49135 and shaping, e.g., cutting or bending, etc.

Abstract

An electronic component includes a substrate; a piezoelectric material layer supported directly or indirectly by the substrate; a first electrode arranged on a surface of the piezoelectric material layer on an opposite side of the substrate; and a second electrode arranged on a surface of the piezoelectric material layer on the substrate side. The piezoelectric material layer is sandwiched between the first electrode and the second electrode. The first electrode has a smaller surface area than the piezoelectric material layer. A portion where the piezoelectric material layer is exposed from the first electrode includes a portion that is thinner than a thickness of the piezoelectric material layer between the first electrode and the second electrode. Thus, it is possible to configure a resonator with a higher frequency than its ordinary resonance, and it is easy to achieve an adjustment of the resonance frequency of the resonator, as well as improving the yield of the component and enabling the configuration of an electronic component that includes a plurality of resonators of different frequencies.

Claims

1. An electronic component comprising at least one piezoelectric element including:

a substrate;

a piezoelectiic material layer supported directly or indirectly by the substrate;

a first electrode arranged on a principal surface of the piezoelectric material layer;

a second electrode arranged or the other surface of the piezoelectric material layer;

wherein the piezoelectric material layer is sandwiched between the first electrode and the second electrode;

wherein the plezocleotric material layer includes at least a first piezoelectric material area not supported by the substrate and a second piezoelectric material area, other than the first piezoelectric material area, in which the piezoelectric material layer is not supported by the substrate.

wherein, in the piezoelectric material layer, the second electrode is formed at least on the other surface of the first piezoelectric material area and the second piezoelectric material area;

wherein, in the piezoelectric material layer, the first electrode Is formed at least on the principal surface of the first piezoelectric material area; and

wherein a part or an entirety of the second plezocleotric material area has a thickness smaller than that of the first plezocleotric material area;

wherein the substrate does not include an oscillation space, and wherein a multilayer film of an inorganic substance constituting an acoustic mirror is present between the substrate and the second electrode.

2. The electronic component according to claim 1 forming a resonator, wherein the substrate includes an oscillation space, and wherein the piezoelectric material layer includes at least a first piezoelectric material area not supported by the substrate and a second piezoelectric material area, other the first piezoelectric material area, in which the piezoelectric material layer Is not supported by the substrate.

3. The electronic component according to claim 2, wherein a portion of the second piezoelectric material area has a same thickness as the first piezoelectric material area.

4. The electronic component according to claim 2, wherein the electronic component comprises at least two resonators with different resonance frequencies.

5. The electronic component according to claim 4, wherein a thickness of the second piezoelectric material area is the same in an entirety of resonators.

6. The electronic component according to claim 2, comprising a plurality of resonators with different thicknesses of the second piezoelectric material area.

7. The electronic component according to claim 2, comprising a plurality of resonators with different surface areas of the first piezoelectric material area.

8. The electronic component according to claim 1, wherein a thickness of a portion where the piezoelectric material layer is exposed from the first electrode is at least 10 nm and at most 400 nm thinner than a thickness of the piezoelectric material layer between the first electrode and the second electrode.

9. The electronic component according to claim 1, wherein a portion with a thin thickness of a portion where the piezoelectric material layer is exposed horn the first electrode has a stepped shape or a tapered shape.

10. The electronic component according to claim 1, wherein the piezoelectric material is aluminum nitride.

11. The electronic component according to claim 1, wherein the substrate is made of silicon.

12. The electronic component according to claim 1, wherein the first electrode arid the second electrode are made of at least one material selected from a group consisting of gold, molybdenum, tantalum, palladium, platinum, titanium, and tungsten.

13. The electronic component according to claim 1, wherein a resonator of the electronic component does not use an oscillation energy trapping effect.

14. The electronic component according to claim 1, wherein an oscillation mode of the piezoelectric material is thickness longitudinal oscillation.

15. The electronic component according to claim 1, wherein the second piezoelectric material area is formed so as to have a flat surface in a stepped shape with respect to the first piezoelectric material area.