TRANSDUCER AND METHOD FOR FORMING THE SAME

• US 20150145374A1
• Filed: 11/25/2014
• Published: 05/28/2015
• Est. Priority Date: 11/26/2013
• Status: Active Grant

• Current Assignee: Agency For Science Technology and Research (Government of Singapore)
• Original Assignee: Agency For Science Technology and Research (Government of Singapore)
• Inventors: XU, Jinghui, YU, Hongbin, LOU, Liang, GU, Alex Yuandong
• Granted Patent: US 10,076,772 B2
• Time in Patent Office: Days
• US Class Current: 310/317
• CPC Class Codes: B06B 1/0644 using a single piezoelectric element B06B1/0688 takes precedence
• CPC Class Codes: B06B 1/0651 of circular shape
• CPC Class Codes: G10K 9/122 using piezoelectric driving means G10K9/121 takes precedence
• CPC Class Codes: H10N 30/2047 Membrane type
• CPC Class Codes: H10N 30/308 Membrane type
• CPC Class Codes: H10N 30/88 Mounts; Supports; Enclosures; Casings
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

A transducer is provided, which includes a substrate, wherein a cavity is defined at least partially through the substrate, at least one stopper structure arranged within the cavity, a support layer arranged over the at least one stopper structure and the cavity to seal the cavity, and a piezoelectric functional arrangement arranged on the support layer. According to further embodiments of the present invention, a method for forming a transducer is also provided.

Claims

1. A transducer comprising:

a substrate, wherein a cavity is defined at least partially through the substrate;

at least one stopper structure arranged within the cavity;

a support layer arranged over the at least one stopper structure and the cavity to seal the cavity; and

a piezoelectric functional arrangement arranged on the support layer.

2. The transducer as claimed in claim 1, wherein the support layer is arranged directly on the substrate.

3. The transducer as claimed in claim 1, wherein the piezoelectric functional arrangement is arranged directly on the support layer.

4. The transducer as claimed in claim 1, wherein the at least one stopper structure extends from a base surface of the cavity.

5. The transducer as claimed in claim 1, wherein the at least one stopper structure comprises an elongate structure.

6. The transducer as claimed in claim 1, wherein the at least one stopper structure comprises a ring structure.

7. The transducer as claimed in claim 1, wherein the at least one stopper structure comprises a tapered top region.

8. The transducer as claimed in claim 1, wherein the at least one stopper structure comprises a polymer coated top surface.

9. The transducer as claimed in claim 1, wherein the material of the at least one stopper structure is the same as the material of the substrate.

10. The transducer as claimed in claim 1, wherein the transducer comprises a plurality of stopper structures arranged within the cavity.

11. The transducer as claimed in claim 10, wherein the plurality of stopper structures are arranged in at least one concentric pattern.

12. The transducer as claimed in claim 10, wherein adjacent stopper structures of the plurality of stopper structures are arranged spaced apart from each other.

13. The transducer as claimed in claim 1, wherein the support layer comprises a semiconductor layer and an insulating layer arranged one over the other.

14. The transducer as claimed in claim 1, wherein the piezoelectric functional arrangement comprises a pair of electrodes and a piezoelectric element arranged in between the pair of electrodes.

15. The transducer as claimed in claim 1, further comprising an ultrasound frequency signal generating circuit electrically coupled to the piezoelectric functional arrangement.

16. The transducer as claimed in claim 1, further comprising an acoustic signal detector.

17. The transducer as claimed in claim 1, wherein a depth of the cavity is larger than about 1 μ

m.

18. The transducer as claimed in claim 1, wherein in an equilibrium position, a distance between a top surface of the at least one stopper structure and a lower surface of the support layer is between about 0.2 μ

m and about 10 μ

m.

19. The transducer as claimed in claim 1, wherein the cavity is at least substantially vacuum sealed.

20. A method for forming a transducer, the method comprising:

forming a cavity at least partially through a substrate;

forming at least one stopper structure within the cavity;

forming a support layer over the at least one stopper structure and the cavity to seal the cavity; and

forming a piezoelectric functional arrangement on the support layer.