ELECTRONIC DEVICE

• US 20070284971A1
• Filed: 06/12/2007
• Published: 12/13/2007
• Est. Priority Date: 06/12/2006
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yanase, Naoko, Ohara, Ryoichi, Yasumoto, Takaaki, Sano, Kenya
• Application Number:
  US11/761,767
• Publication Number:
  US 20070284971A1
• Time in Patent Office: Days
• US Class Current: 310/364
• CPC Class Codes: H03H 9/02094 of adherence
• CPC Class Codes: H03H 9/13 for networks consisting of piezoelectric or electrostrictive materials H03H9/145 takes precedence
• CPC Class Codes: H03H 9/131 consisting of a multilayered structure
• CPC Class Codes: H03H 9/173 Air-gaps
• CPC Class Codes: H03H 9/174 Membranes
• CPC Class Codes: H04R 17/02 Microphones
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• CPC Class Codes: H10N 30/2042 Cantilevers, i.e. having one fixed end
• CPC Class Codes: H10N 30/2047 Membrane type
• CPC Class Codes: H10N 30/877 Conductive materials in general H01B1/00

Abstract

An electronic device includes: a lower electrode; a first piezoelectric film provided on the lower electrode; and an upper electrode provided on the first piezoelectric film. At least one of the lower electrode and the upper electrode is made of an alloy composed primarily of aluminum and doped with at least one element selected from the group consisting of Ni, Co, V, Ta, Mo, W, Ti, Y, and Nd. Alternatively, an electronic device includes: a support substrate; a lower electrode provided on the support substrate; a first piezoelectric film provided on the lower electrode; and an upper electrode provided on the first piezoelectric film. The lower electrode is made of an alloy composed primarily of aluminum and doped with at least one element selected from the group consisting of Ni, Co, V, Ta, Mo, W, Ti, Y, and Nd.

Claims

1. An electronic device comprising:

a lower electrode;

a first piezoelectric film provided on the lower electrode; and

an upper electrode provided on the first piezoelectric film,

at least one of the lower electrode and the upper electrode being made of an alloy composed primarily of aluminum and doped with at least one element selected from the group consisting of Ni, Co, V, Ta, Mo, W, Ti, Y, and Nd.

2. The electronic device according to claim 1, wherein the alloy contains aluminum at 90 to 99.5 atomic percent.

3. The electronic device according to claim 1, wherein the lower electrode is made of the alloy, and is a polycrystal having a <

111>

orientation half-width of 4 degrees or less.

4. The electronic device according to claim 1, further comprising:

a buffer layer provided below the lower electrode and made of amorphous alloy film.

5. The electronic device according to claim 1, wherein the first piezoelectric film is made of AlN.

6. The electronic device according to claim 1, wherein the lower electrode contains Ni at 2 atomic percent or more.

7. The electronic device according to claim 6, wherein the lower electrode contains Ni at 10 atomic percent or less.

8. The electronic device according to claim 1, wherein the lower electrode contains Ta at 5 atomic percent or more.

9. The electronic device according to claim 8, wherein the lower electrode contains Ta at 10 atomic percent or less.

10. The electronic device according to claim 1, further comprising a support substrate having a hollow portion, wherein at least a part of the lower electrode is provided on the hollow portion.

11. The electronic device according to claim 1, further comprising a support substrate having a hollow portion,

wherein the lower electrode is provided on the support substrate, and cavity is provided between the support substrate and the lower electrode.

12. The electronic device according to claim 1, further comprising:

a support substrate; and

an anchor provided on the support substrate,

wherein one end of the lower electrode is supported on the support substrate through the anchor.

13. The electronic device according to claim 12, further comprising:

an intermediate electrode provided between the first piezoelectric film and the upper electrode; and

a second piezoelectric film provided between the intermediate electrode and the upper electrode.

14. The electronic device according to claim 13, wherein the intermediate electrode is made of the same material as the lower electrode.

15. An electronic device comprising:

a support substrate;

a lower electrode provided on the support substrate;

a first piezoelectric film provided on the lower electrode; and

an upper electrode provided on the first piezoelectric film,

the lower electrode being made of an alloy composed primarily of aluminum and doped with at least one element selected from the group consisting of Ni, Co, V, Ta, Mo, W, Ti, Y, and Nd.

16. The electronic device according to claim 15, wherein the lower electrode is made of the alloy, and is a polycrystal having a <

111>

orientation half-width of 4 degrees or less.

17. The electronic device according to claim 15, wherein the lower electrode contains Ni at 2 atomic percent or more.

18. The electronic device according to claim 15, wherein the lower electrode contains Ni at 10 atomic percent or less.

19. The electronic device according to claim 15, wherein the lower electrode contains Ta at 5 atomic percent or more

20. The electronic device according to claim 15, wherein the lower electrode contains Ta at 10 atomic percent or less.