Methods of fabricating MEMS with spacers between plates and devices formed by same

• US 8,284,475 B2
• Filed: 04/01/2010
• Issued: 10/09/2012
• Est. Priority Date: 05/11/2007
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Sampsell, Jeffrey Brian, Gally, Brian James, Floyd, Philip Don
• Primary Examiner(s): Choi, William
• Application Number:
  US12/752,982
• Publication Number:
  US 20100182675A1
• Time in Patent Office: 922 Days
• Field of Search: 359/198.1, 359/223.1, 359/230, 359/231, 359/290, 359/291
• US Class Current: 359/290
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 2207/092 Buried interconnects in the substrate or in the lid
• CPC Class Codes: B81B 3/007 For controlling stiffness, e.g. ribs
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26
• CPC Class Codes: H01L 31/04 adapted as photovoltaic [PV] conversion devices testing thereof during manufacture H01L22/00; testing thereof after manufacture H02S50/10
• CPC Class Codes: Y10T 29/49126 Assembling bases

Abstract

Methods of fabricating a microelectromechanical systems (MEMS) device with spacers between plates and MEMS devices formed by the same are disclosed. In one embodiment, a MEMS device is fabricated by laminating a front substrate and a carrier, each of which has components preformed thereon. The front substrate is provided with stationary electrodes formed thereover. A carrier including movable electrodes formed thereover is attached to the front substrate. The carrier of some embodiments is released after transferring the movable electrodes to the front substrate. In other embodiments, the carrier stays over the front substrate, and serves as a backplate for the MEMS device. Features are formed by deposition and patterning, by embossing, or by patterning and etching. Spacers are provided between the front substrate and the backplate to maintain a gap therebetween. The methods not only reduce the manufacturing costs, but also provide a higher yield. The resulting MEMS devices can trap smaller volumes between laminated substrates and are less susceptible to pressure variations and moisture leakage.

Claims

1. A microelectromechanical system (MEMS) device, comprising:

a front substrate comprising a first support extending from the front substrate;

a backplate having a surface substantially opposing the front substrate such that the first support is interposed between the front substrate and the surface of the backplate;

a moving electrode interposed between the front substrate and backplate, the moving electrode comprising a portion supported on the first support; and

a second support extending from and integrally formed with the surface of the backplate, wherein the second support is positioned between the first support of the front substrate and the surface of the backplate.

2. The device of claim 1, wherein the first support comprises at least one of a post and a rail.

3. The device of claim 1, wherein the second support comprises a post.

4. The device of claim 1, wherein the portion of the moving electrode is interposed between the first support and the second support.

5. The device of claim 1, wherein the portion of the moving electrode comprises an opening and wherein the second support extends through the opening of the portion of the moving electrode.

6. The device of claim 1, wherein the second support is laterally spaced apart from the portion of the moving electrode.

7. The device of claim 1, wherein the MEMS device comprises an interferometric modulator.

8. A method of making a microelectromechanical system (MEMS) device, the method comprising:

providing a front substrate comprising a first support extending from the front substrate;

providing a backplate having a surface;

attaching the front substrate to the backplate such that the first support is interposed between the front substrate and the surface of the backplate; and

forming a second support between the first support of the front substrate and the surface of the backplate such that the second support extends from and is integrally formed with the surface of the backplate, wherein the second support comprises a post.

9. The method of claim 8, wherein the first support comprises a rail.

10. The method of claim 8, wherein forming the second support comprises forming the second support of the same material as the first support.

11. The method of claim 8, wherein forming the second support comprises forming the second support on the surface of the backplate before attaching the front substrate to the backplate.

12. The method of claim 8, wherein forming the second support comprises forming the second support of the same material as the backplate.

13. The method of claim 8, wherein forming the second support comprises etching the backplate.

14. A method of making a microelectromechanical system (MEMS) device, the method comprising:

providing a front substrate comprising a first support extending from the front substrate;

providing a backplate having a surface;

providing a moving electrode between the front substrate and the backplate such that a portion of the moving electrode is supported on the first support;

attaching the front substrate to the backplate such that the first support is interposed between the front substrate and the surface of the backplate; and

forming a second support between the first support of the front substrate and the surface of the backplate such that the second support extends from and is integrally formed with the surface of the backplate.

15. The method of claim 14, wherein forming the second support comprises forming the second support such that the portion of the moving electrode is interposed between the first support and the second support.

16. The method of claim 14, wherein forming the second support comprises forming the second support such that the second support penetrates the portion of the moving electrode.

17. The method of claim 14, wherein forming the second support comprises forming the second support such that the second support is laterally spaced apart from the portion of the moving electrode.

18. A method of making a microelectromechanical system (MEMS) device, the method comprising:

providing a front substrate comprising a first support extending from the front substrate;

providing a backplate having a surface;

attaching the front substrate to the backplate such that the first support is interposed between the front substrate and the surface of the backplate; and

forming a second support between the first support of the front substrate and the surface of the backplate such that the second support extends from and is integrally formed with the surface of the backplate, wherein forming the second support comprises forming the second support to contact the first support of the front substrate.

19. A method of making a microelectromechanical system (MEMS) device, the method comprising:

providing a front substrate comprising a first support extending from the front substrate;

providing a backplate having a surface;

attaching the front substrate to the backplate such that the first support is interposed between the front substrate and the surface of the backplate; and

forming a second support between the first support of the front substrate and the surface of the backplate such that the second support extends from and is integrally formed with the surface of the backplate, wherein forming the second support comprises embossing the backplate.