Technique for forming a MEMS device

Patent metadata

Field	Value
Publication number	US-9260290-B2
Application number	US-201414494688-A
Country	US
Kind code	B2
Filing date	Sep 24, 2014
Priority date	Mar 30, 2011
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

An apparatus is formed on a substrate including at least one semiconductor device. The apparatus includes a microelectromechanical system (MEMS) device comprising at least one of a portion of a first structural layer and a portion of a second structural layer formed above the first structural layer. The second structural layer has a thickness substantially greater than a thickness of the first structural layer. In at least one embodiment, the MEMS device includes a first portion of the second structural layer and a second portion of the second structural layer. In at least one embodiment, the MEMS device further comprises a gap between the first portion of the second structural layer and the second portion of the second structural layer. In at least one embodiment, the gap has a width at least one order of magnitude less than the thickness of the second structural layer.

First claim

What is claimed is:

1. An apparatus formed on a substrate including at least one semiconductor device, the apparatus comprising:
a microelectromechanical system (MEMS) device comprising a portion of a first structural layer and a portion of a second structural layer formed above the first structural layer, the second structural layer having a thickness greater than a thickness of the first structural layer,
wherein the MEMS device comprises a member comprising the portion of the first structural layer and the portion of the second structural layer,
wherein the portion of the second structural layer is an attachment attached to the first portion of the first structural layer.

2. The apparatus, as recited in claim 1 , wherein the portion of the second structural layer increases the mass of the member of the MEMS device formed by the portion of the first structural layer.

3. The apparatus, as recited in claim 1 , wherein the MEMS device comprises a first portion of the second structural layer and a second portion of the second structural layer, the MEMS device further comprising: a gap between the first portion of the second structural layer and the second portion of the second structural layer, the gap having a width at least one order of magnitude less than the thickness of the second structural layer.

4. The apparatus, as recited in claim 3 , wherein the first and second portions of the second structural layer form electrically isolated, electrostatically coupled portions of the MEMS device.

5. The apparatus, as recited in claim 1 , wherein the MEMS device comprises a first portion of the second structural layer and a second portion of the second structural layer, wherein an electrode of the MEMS device comprises the first portion of the second structural layer and a member of the MEMS device comprises the second portion of the second structural layer.

6. The apparatus, as recited in claim 5 , wherein the member is a mass of an inertial sensor.

7. The apparatus, as recited in claim 6 , wherein a first portion of the first structural layer forms an anchor for the mass and is electrically coupled to the mass.

8. The apparatus, as recited in claim 1 , further comprising:
at least one electrical contact coupling the MEMS device to a semiconductor device of the at least one semiconductor device.

9. The apparatus, as recited in claim 1 , wherein the second structural layer has a thickness of at least two times the thickness of the first structural layer.

10. The apparatus, as recited in claim 1 , wherein the second structural layer has a thickness of at least five times the thickness of the first structural layer.

11. The apparatus, as recited in claim 1 , wherein the second structural layer comprises a plurality of layers of a first thickness of a first material, an interface between a first layer of the plurality of layers and a second layer of the plurality of layers comprising an oxide interface.

12. The apparatus, as recited in claim 1 , wherein the portion of the second structural layer is in direct contact with the portion of the first structural layer.

13. The apparatus, as recited in claim 3 , wherein the portion of the second structural layer is an attachment attached to the first portion of the first structural layer.

14. The apparatus, as recited in claim 1 , wherein the attachment comprises a filler and a coating conforming to the filler.

15. An apparatus comprising:
an electrode of a microelectromechanical system (MEMS) device formed above a substrate including a semiconductor device; and
a member of the MEMS device, the member being formed above the substrate and electrostatically coupled to the electrode, the member including a portion of a first structural layer and a portion of a second structural layer formed above the first structural layer, wherein the portion of the second structural layer has a higher mass than the portion of the first structural layer,
wherein the portion of the second structural layer is an attachment attached to the first portion of the first structural layer.

16. The apparatus, as recited in claim 15 , further comprising:
a gap between the electrode and the member, the gap having a width at least one order of magnitude less than the thickness of the second structural portion,
wherein in operation of a microelectromechanical system (MEMS) device including the electrode and the member, the electrode is electrostatically coupled to the member across the gap.

17. The apparatus, as recited in claim 15 , wherein the electrode comprises:
a portion of the first structural layer; and
a portion of the second structural layer, the second structural layer having a thickness greater than a thickness of the first structural layer.

18. The apparatus, as recited in claim 15 , wherein the attachment comprises a filler and a coating conforming to the filler.

19. The apparatus, as recited in claim 15 , wherein the attachment is conjoined with the first portion of the structural layer and the first portion of the structural layer and the attachment are operative to move in unison.

Assignees

• Silicon Lab Inc

Inventors

• Quevy Emmanuel P
• Low Carrie W
• Hui Jeremy Ryan
• Gu Zhen

Classifications

• G01C19/5712

  the devices involving a micromechanical structure · CPC title

• B81C2203/0735

  Post-CMOS, i.e. forming the micromechanical structure after the CMOS circuit · CPC title

• B81C1/00246 Primary

  Monolithic integration, i.e. micromechanical structure and electronic processing unit are integrated on the same substrate · CPC title

• B81B2207/015

  the micromechanical device and the control or processing electronics being integrated on the same substrate · CPC title

• B81B2201/0242

  Gyroscopes · CPC title