Micro-electro-mechanical transducer having an optimized non-flat surface

• US 10,029,912 B2
• Filed: 03/09/2015
• Issued: 07/24/2018
• Est. Priority Date: 08/03/2005
• Status: Active Grant

• Current Assignee: Kolo Medical, Ltd.
• Original Assignee: Kolo Technologies, Inc.
• Inventors: Huang, Yongli
• Primary Examiner(s): Tran, Anh
• Application Number:
  US14/642,453
• Publication Number:
  US 20150180370A1
• Time in Patent Office: 1,233 Days
• Field of Search: None
• CPC Class Codes: B06B 1/0292 Electrostatic transducers, e.g. electret-type
• CPC Class Codes: B81B 3/0027 Structures for transforming mechanical energy, e.g. potential energy of a spring into translation, sound into translation
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: B81C 1/00182 Arrangements of deformable or non-deformable structures, e.g. membrane and cavity for use in a transducer
• CPC Class Codes: B81C 1/00357 involving bonding one or several substrates on a non-temporary support, e.g. another substrate
• CPC Class Codes: B81C 1/00373 Selective deposition, e.g. printing or microcontact printing
• CPC Class Codes: B81C 1/00523 Etching material
• CPC Class Codes: B81C 1/00626 Processes for achieving a desired geometry not provided for in groups B81C1/00563 - B81C1/00619
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: H03H 3/0072 of microelectro-mechanical resonators or networks micromembranes or microbeams B81B2203/01; manufacture of microstructural devices in general B81C
• CPC Class Codes: H03H 9/02259 Driving or detection means
• CPC Class Codes: H03H 9/2405 of microelectro-mechanical resonators
• CPC Class Codes: H03H 9/462 Microelectro-mechanical filters
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer

Abstract

A capacitive micromachined ultrasound transducer (cMUT) is provided. The cMUT has a first layer having a first electrode and a second layer having a second electrode opposing the first electrode to define a gap width therebetween. At least one of the first layer and the second layer includes a flexible layer having a contact area in contact to a support, such that the first electrode and the second electrode are movable relative to each other to cause a change of the gap width. The support has two substantially continuous shoulder sides each extending along with the flexible layer, each shoulder side making graduated contact with more contact area of the flexible layer as the flexible layer deforms toward the shoulder side, causing the flexible layer to have a dynamically changing spring strength.

Claims

1. A capacitive micromachined ultrasound transducer (cMUT) comprising:

a first layer having a first electrode; and

a second layer having a second electrode opposing the first electrode to define a gap width therebetween,

wherein at least one of the first layer and the second layer includes a flexible layer having a contact area in contact to a support, such that the first electrode and the second electrode are movable relative to each other to cause a change of the gap width; and

wherein the support has two substantially continuous shoulder sides each extending along with the flexible layer, each shoulder side making graduated contact with more contact area of the flexible layer as the flexible layer deforms toward the shoulder side, causing the flexible layer to have a dynamically changing spring strength.

2. The cMUT of claim 1, wherein the support is disposed between the first layer and the second layer, and in contact with both the first layer and the second layer.

3. The cMUT of claim 2, wherein the first layer includes the flexible layer, and the second layer includes the support with its substantially continuous shoulder sides.

4. The cMUT of claim 2, wherein the first layer includes the flexible layer, and the first layer includes the support with its substantially continuous shoulder sides.

5. The cMUT of claim 1, wherein the support with its substantially continuous shoulder sides is at least partially made out of a native material of one of the first layer and the second layer.

6. The cMUT of claim 1, wherein the support is placed under both the first layer and the second layer, and in contact of the second layer.

7. The cMUT of claim 1, wherein the support is a part of a substrate.

8. The cMUT of claim 1, wherein the shoulder side of the support has a substantially smooth surface, such that the change of the gap width is substantially continuous.

9. The cMUT of claim 1, wherein the shoulder side includes a part of one of the first electrode and the second electrode, the shoulder side having a shape profile optimized to compensate a dynamic deformation of the other one of the first electrode and the second electrode to reduce non-uniformity of the gap width during operation.

10. A micro-electro-mechanical transducer comprising:

a first layer having a first electrode; and

a second layer having a second electrode opposing the first electrode to define a gap width therebetween,

wherein at least one of the first layer and the second layer includes a flexible layer having a contact area in contact to a support, such that the first electrode and the second electrode are movable relative to each other to cause a change of the gap width; and

wherein the support has two substantially continuous shoulder sides each extending along with the flexible layer, each shoulder side positioned relative to the flexible layer to make graduated contact with an increasing contact area of the flexible layer as the flexible layer deforms toward the shoulder side.

11. The micro-electro-mechanical transducer of claim 10, wherein the support is disposed between the first layer and the second layer, and in contact with both the first layer and the second layer.

12. The micro-electro-mechanical transducer of claim 11, wherein the first layer includes the flexible layer, and the second layer includes the support with its substantially continuous shoulder sides.

13. The micro-electro-mechanical transducer of claim 11, wherein the first layer includes the flexible layer, and the first layer includes the support with its substantially continuous shoulder sides.

14. The micro-electro-mechanical transducer of claim 10, wherein the support with its substantially continuous shoulder sides is at least partially made out of a native material of one of the first layer and the second layer.

15. The micro-electro-mechanical transducer of claim 10, wherein the support is placed under both the first layer and the second layer, and in contact of the second layer.

16. The micro-electro-mechanical transducer of claim 10, wherein the support is a part of a substrate.

17. The micro-electro-mechanical transducer of claim 10, wherein the shoulder side of the support has a substantially smooth surface, such that the change of the gap width is substantially continuous.

18. The micro-electro-mechanical transducer of claim 10, wherein the shoulder side includes a part of one of the first electrode and the second electrode, the shoulder side having a shape profile optimized to compensate a dynamic deformation of the other one of the first electrode and the second electrode to reduce non-uniformity of the gap width during operation.