MEMS device and MEMS vacuum microphone

Patent metadata

Field	Value
Publication number	US-9828237-B2
Application number	US-201615066741-A
Country	US
Kind code	B2
Filing date	Mar 10, 2016
Priority date	Mar 10, 2016
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

In accordance with an embodiment, a MEMS device includes a first membrane element, a second membrane element spaced apart from the first membrane element, a low pressure region between the first and second membrane elements, the low pressure region having a pressure less than an ambient pressure, and a counter electrode structure comprising a conductive layer, which is at least partially arranged in the low pressure region or extends in the low pressure region. The conductive layer includes a segmentation providing an electrical isolation between a first portion of the conductive layer and a second portion of the conductive layer.

First claim

What is claimed is:

1. A MEMS device comprising:
first membrane element,
a second membrane element spaced apart from the first membrane element,
a low pressure region between the first and second membrane elements, the low pressure region having a pressure less than an atmospheric pressure, and
a counter electrode structure comprising a conductive layer, which is at least partially arranged in the low pressure region or extends in the low pressure region, wherein the conductive layer comprises a segmentation providing an electrical isolation between a first portion of the conductive layer and a second portion of the conductive layer.

2. The MEMS device according to claim 1 , wherein the segmentation of the conductive layer is a circumferential narrow gap in the conductive layer.

3. The MEMS device according to claim 1 , wherein the first membrane element comprises a displaceable portion and a fixed portion, wherein the second membrane element comprises a displaceable portion and a fixed portion, and wherein the first portion of the conductive layer is arranged between the displaceable portion of the first membrane element and the displaceable portion of the second membrane element.

4. The MEMS device according to claim 1 , wherein the first portion of the conductive layer is a central portion of the conductive layer, and wherein the second portion of the conductive layer is a fringe portion of the conductive layer.

5. The MEMS device according to claim 1 , wherein the second portion of the conductive layer is electrically coupled to the first membrane element and to the second membrane element.

6. The MEMS device according to claim 1 , wherein the first and second membrane elements are mechanically coupled.

7. The MEMS device according to claim 1 , wherein the first and second membrane elements are electrically connected.

8. The MEMS device according to claim 1 , wherein one or more pillars are mechanically coupled between the first membrane element and the second membrane element.

9. The MEMS device according to claim 1 , wherein the pressure in the low pressure region is substantially a vacuum.

10. The MEMS device according to claim 1 , wherein the low pressure region is within a sealed cavity, which is formed between the first membrane element and the second membrane element.

11. The MEMS device according to claim 1 , wherein the counter electrode structure comprises a further conductive layer, wherein a further segmentation provides an electrical isolation between a first portion of the further conductive layer and a second portion of the further conductive layer, and wherein the first portion of the further conductive layer is electrically isolated from the first portion of the first conductive layer.

12. The MEMS device according to claim 11 , wherein one or more pillars are mechanically coupled between the first and second membrane elements, and wherein the one or more pillars are electrically conductive for providing a mechanical and electrical coupling between the first and second membrane elements.

13. The MEMS device according to claim 12 , wherein the first portion of the further conductive layer is a central portion of the further conductive layer, and wherein the second portion of the further conductive layer is a fringe portion of the further conductive layer.

14. The MEMS device according to claim 12 , wherein the first membrane element comprises a displaceable portion and a fixed portion, wherein the second membrane element comprises a displaceable portion and a fixed portion, wherein the first portion of the conductive layer faces the displaceable portion of the first membrane element, and wherein the first portion of the further conductive layer faces the displaceable portion of the second membrane element.

15. The MEMS device according to claim 12 , wherein the second portion of the conductive layer is electrically connected to the first membrane element, and wherein the second portion of the further conductive layer is electrically connected to the second membrane element.

16. The MEMS device according to claim 12 , wherein the segmentation of the further conductive layer is a circumferential narrow gap in the further conductive layer, and the segmentation of the conductive layer is a circumferential narrow gap in the conductive layer.

17. The MEMS device according to claim 16 , wherein a first spacer element is arranged between the first membrane element and the conductive layer, wherein a second spacer element is arranged between the second membrane element and the further conductive layer, and wherein the circumferential narrow gap in the conductive layer is located outside the first spacer element, and the circumferential narrow gap in the further conductive layer is located outside the second spacer element.

18. The MEMS device according to claim 16 , wherein the circumferential narrow gap in the conductive layer is, with respect to a vertical projection, laterally offset to the circumferential narrow gap in the further conductive layer.

19. The MEMS device according to claim 16 , wherein the circumferential narrow gap in the conductive layer and the circumferential narrow gap in the further conductive layer are arranged in a non-overlapping configuration.

20. The MEMS device according to claim 16 , wherein at least one of the circumferential narrow gap in the conductive layer and the circumferential narrow gap in the further conductive layer is completely filled with an isolating material.

21. The MEMS device according to claim 1 , wherein the MEMS device is a MEMS microphone.

22. A MEMS device comprising:
a first membrane element,
a second membrane element spaced apart from the first membrane element,
a low pressure region between the first and second membrane elements, the low pressure region having a pressure less than an atmospheric pressure, and
a counter electrode structure comprising a first conductive layer which is at least partially arranged in the low pressure region or extends in the low pressure region,
wherein the first membrane element comprises a segmentation providing an electrical isolation between a first portion of the first membrane element and a second portion of the first membrane element, and
wherein the second membrane element comprises a further segmentation comprising an electrical isolation between a first portion of the second membrane element and a second portion of the second membrane element.

23. The MEMS device according to claim 22 , wherein the segmentation of the first membrane element is a circumferential narrow gap in the first membrane element, and wherein the segmentation of the second membrane element is a circumferential narrow gap in the second membrane element.

24. The MEMS device according to claim 22 , wherein the first portion of the first membrane element is a center portion of the first membrane element, and wherein the second portion of the first membrane element is a fringe portion of the first membrane element, and wherein the first portion of the second membrane element is a center portion of the second membrane element, and wherein the second portion of the second membrane element is a fringe portion of the second membrane element.

25. The MEMS device according to claim 22 , wherein the first portion of the first membrane element and the first portion of the second membrane element are electrically coupled to the first conductive layer.

Assignees

• Infineon Technologies Ag

Inventors

• Walther Arnaud
• Dehe Alfons
• Strasser Johann
• Metzger-Brueckl Gerhard

Classifications

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R31/006

  Interconnection of transducer parts (of diaphragm and outer suspension by moulding H04R31/003) · CPC title

• H04R19/005 Primary

  using semiconductor materials · CPC title

• B81B2203/0127

  Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function · CPC title

• B81B3/0086 Primary

  Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage · CPC title