Film bulk acoustic resonator (FBAR) and the method of making the same

• US 20030141946A1
• Filed: 01/31/2002
• Published: 07/31/2003
• Est. Priority Date: 01/31/2002
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Seo, Kuhn, Kekoa, Alexia P., Volcjak, Teresa, Ruby, Richard C., Sridharan, Urupattur C., Chien, Allen
• Application Number:
  US10/062,899
• Publication Number:
  US 20030141946A1
• Time in Patent Office: Days
• US Class Current: 333/187
• CPC Class Codes: H03H 2003/0471 of a plurality of resonators at different frequencies
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence

Abstract

An apparatus having a thin film bulk acoustic resonator (FBAR) with positively sloped bottom electrode and a method of making the same is disclosed. The resonator has a bottom electrode, a top electrode, and core material. The bottom electrode includes a positively sloped edge. To make the apparatus including the resonator, first, a bottom electrode layer is deposited. Then, the bottom electrode layer is dry etched to fabricate a bottom electrode having a positively sloped edge. Next, a core layer is fabricated above the bottom electrode. Finally, a top electrode is fabricated over the core layer.

Claims

1. An apparatus comprising a resonator including a bottom electrode, a top electrode and core material, the bottom electrode having a positively sloped edge.

2. The apparatus recited in claim 1 wherein the slope is at an angle ranging between 5 degrees and 60 degrees.

3. The apparatus recited in claim 1 wherein the resonator is a film bulk acoustic resonator (FBAR).

4. The apparatus recited in claim 1 wherein the bottom electrode comprises conductive metal.

5. The apparatus recited in claim 4 wherein the conductive metal is an element selected from a group consisting of Molybdenum, Tungsten, and Aluminum.

6. The apparatus recited in claim 1 wherein the bottom electrode comprises Molybdenum.

7. The apparatus recited in claim 1 wherein core material comprises piezoelectric (PZ) material.

8. The apparatus recited in claim 7 wherein PZ material comprises Aluminum Nitride (AlN).

9. The apparatus recited in claim 1 wherein the first bottom electrode comprises Molybdenum.

10. The apparatus recited in claim 1 further comprising another resonator including a bottom electrode having a positively sloped edge.

11. The apparatus recited in claim 1 wherein the resonator is fabricated on a substrate having a cavity under the resonator.

12. A method for fabricating a resonator, the method comprising:

depositing a bottom electrode layer;

dry etching the bottom electrode layer to fabricate a bottom electrode having a positively sloped edge;

fabricating a core layer above the bottom electrode; and

fabricating a top electrode above the core layer.

13. The method recited in claim 12 wherein the slope is at an angle ranging between 5 degrees and 60 degrees.

14. The method recited in claim 12 wherein the resonator is a film bulk acoustic resonator (FBAR).

15. The apparatus recited in claim 12 wherein the bottom electrode comprises conductive metal.

16. The apparatus recited in claim 15 wherein the conductive metal is an element selected from a group consisting of Molybdenum, Tungsten, and Aluminum.

17. The method recited in claim 12 wherein the bottom electrode comprises Molybdenum.

18. The method recited in claim 12 wherein core material comprises piezoelectric (PZ) material.

19. The method recited in claim 18 wherein PZ material comprises Aluminum Nitride (AlN).

20. The method recited in claim 19 wherein the first bottom electrode comprises Molybdenum.

21. The method recited in claim 12 further comprising another resonator including a bottom electrode having a positively sloped edge.

22. The apparatus recited in claim 12 wherein the resonator is fabricated on a substrate having a cavity under the resonator.