Single-crystal-silicon ribbon hinges for micro-mirror and MEMS assembly on SOI material

• US 6,654,155 B2
• Filed: 11/29/2000
• Issued: 11/25/2003
• Est. Priority Date: 11/29/2000
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sun, Decai, Rosa, Michel A.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US09/724,329
• Publication Number:
  US 20020064647A1
• Time in Patent Office: 1,091 Days
• Field of Search: 359/290, 359/291, 359/292, 359/248, 359/223, 359/224, 359/225, 359/230, 359/231, 359/232, 439/492, 439/87, 439/31, 439/852, 439/856, 439/496, 174/138.R, 174/138.C
• US Class Current: 359/290
• CPC Class Codes: B81B 2203/058 Rotation out of a plane parallel to the substrate
• CPC Class Codes: B81B 7/0006 Interconnects
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

Provided is a micro-electromechanical assembly including an out-of-plane device formed on a device layer of a single crystal silicon substrate. A ribbon structure is formed on the device layer, where the ribbon structure has at least one of a width or depth, which is less than the width or depth of the out-of-plane device. A connection interface provides a connection point between a first end of the out-of-plane device and a first end of a ribbon structure, wherein the ribbon structure and out-of-plane device are integrated as a single piece.

Claims

1. A micro-electromechanical assembly comprising:

an out-of-plane device formed in a single-crystal-silicon device layer of a silicon-on-insulator substrate and;

a flexible ribbon structure formed in the device layer, wherein the out-of-plane device and ribbon structure are both single-crystal-silicon single layer components from the same single-crystal-silicon device layer formed as an integrated assembly, and the ribbon structure has a thickness of between approximately 400 nm to 600 nm, a width of between approximately 25 μ

m to 75 μ

m, and a length of between approximately 70 μ

m to 210 μ

m.

2. The invention according to claim 1 wherein the device layer is formed as part of a silicon-on-insulator wafer, including at least the device layer and a buried oxide layer.

3. The invention according to claim 2 wherein the out-of-plane device is fabricated from a silicon-on-insulator wafer has an initial uniform device layer thickness.

4. The invention according to claim 2 wherein a first end of the ribbon structure is attached to an anchor point above the buried oxide layer, and a second end of the out-of-plane device is unattached to the buried oxide layer.

5. The invention according to claim 1 wherein the ribbon structure has at least one of a width or thickness which is less than at least one of a width or thickness of the out-of-place device.

6. The invention according to claim 1 wherein the out-of-plane device is a micro-mirror.

7. The invention according to claim 1 wherein the ribbon is a micro-hinge.

8. A micro-electromechanical assembly comprising:

an out-of-plane device formed in a single-crystal-silicon device layer of a silicon-on insulator substrate and;

a flexible ribbon structure formed in the device layer, wherein the out-of-plane device and ribbon structure are formed as an integrated assembly, and the ribbon is configured with a mechanical integrity which permits application of a side-twisting mechanical torque to the out-of-plane device sufficient to twist the out-of-plane device to 90°

or more from an initial 0°

twisted position.

9. The invention according to claim 8 wherein the device layer is formed as part of a silicon-on-insulator wafer, including at least the device layer and a buried oxide layer.

10. The invention according to claim 9 wherein a first end of the ribbon structure is attached to an anchor point above the buried oxide layer, and a second end of the out-of-plane device is unattached to the buried oxide layer.

11. The invention according to claim 8 wherein the ribbon structure has a thickness of between approximately 400 nm to 600 nm, a width of between 25 μ

m-75 μ

m, and a length of between 70 μ

m and 210 μ

m.

12. The invention according to claim 8 wherein the out-of-plane device is a micro-mirror.

13. The invention according to claim 8 wherein the ribbon is a micro-hinge.

14. A micro-electromechanical assembly comprising:

an out-of-plane device formed in a single-crystal-silicon device layer of a silicon-on-insulator substrate and;

a flexible ribbon structure formed in the device layer, wherein the out-of-plane device and ribbon structure are formed as an integrated assembly, and wherein the ribbon is configured with a mechanical integrity which permits application of a lifting out-of-plane mechanical torque to lift the out-of-plane device from 0°

which is in the horizontal plane, to 90°

or more out of the horizontal plane.

15. The invention according to claim 14 wherein the device layer is formed as part of a silicon-on-insulator wafer, including at least the device layer and a buried oxide layer.

16. The invention according to claim 15 wherein a first end of the ribbon structure is attached to an anchor point above the buried oxide layer, and a second end of the out-of-plane device is unattached to the buried oxide layer.

17. The invention according to claim 14 wherein the ribbon structure has a thickness of between approximately 400 nm to 600 nm, a width of approximately between 25 μ

m to 75 μ

m, and a length of between approximately 70 μ

m to 210 μ

m.

18. The invention according to claim 14 wherein the out-of-plane device is a micro-mirror.

19. The invention according to claim 14 wherein the ribbon is a micro-hinge.