Optical-electrical MEMS devices and method

• US 6,633,426 B2
• Filed: 05/10/2001
• Issued: 10/14/2003
• Est. Priority Date: 05/10/2001
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Hsu, Charles, Romanowicz, Bart, Laudon, Matt, Shrauger, Vernon
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/853,009
• Publication Number:
  US 20020167712A1
• Time in Patent Office: 887 Days
• Field of Search: 359/290, 359/291, 359/292, 359/295, 359/298, 359/224, 359/230, 348/771, 372/19, 372/20, 372/45, 427/162, 427/534, 257/415, 257/678, 257/723
• US Class Current: 359/290
• CPC Class Codes: B81B 7/0006 Interconnects
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A novel optical-electrical MEMS device overlaid or covered with an optically transmissive substrate held spaced in inverted preferably flip-chip bonded fashion to the device, with transparent electrodes provided in the substrate for generating an upper mirror-actuating field to supplemental the customary lower mirror-well field, enabling complementary operation.

Claims

1. An optical-electrical MEMS device carrying an electrical signal-controllable orientable mirror and covered by an optically transmissive substrate mounted spaced above the mirror;

and means for generating an upper electrical field in the space above the mirror and under said substrate for controlling the mirror orientation.

2. The MEMS device as claimed in claim 1 wherein the electrical field generating means comprises transparent or light-transmissive electrodes disposed on said substrate.

3. The MEMS device as claimed in claim 2 wherein the mirror is mounted in a well of the device and is also controlled by a further lower electrical field generated in the well below the mirror.

4. The MEMS device as claimed in claim 3 wherein means is provided for operating the upper and lower electrical fields in complementary fashion.

5. The MEMS device as claimed in claim 3 wherein means is provided to apply dynamically advantageous upper and lower electrostatic force distributions to enhance the dynamic behavior and response of the MEMS device.

6. The MEMS device as claimed in claim 5 wherein electrostatic restoring forces are provided.

7. An optical-electrical MEMS device carrying an electrical signal-controllable orientable mirror mounted within a well in the device and provided with electrodes for applying a lower voltage field within the well below the mirror for generating electrical signals for controlling the orientation of the mirror within the well;

an optically-transmissive substrate integrally attached by spacer posts to cover or overlay the MEMS device and its mirror-mounting well, but providing sufficient space between the substrate and the mirror to avoid interference with the orienting operation of the mirror; and

transparent electrodes provided on the optically-transmissive substrate for applying an upper voltage field above the well to supplement the lower voltage field within the well in controlling the electrical signal-orientable mirror.

8. The MEMS device of claim 7 wherein the mirror is torsion-spring mounted within the well and orientable in response to the field voltages.

9. The MEMS device of claim 7 wherein the transparent electrodes are provided at the lower surface of the substrate facing the MEMS device mirror and well.

10. The MEMS device of claim 9 wherein the substrate carries passive optical components monolithically integrated into the light-transmissive substrate and optically interacting therewith.

11. The MEMS device of claim 9 wherein the substrate carries active optical elements including light-producing, transmitting, receiving or detecting elements attached thereto for light-path interfacing therewith.

12. The MEMS device of claim 7 wherein the lower and upper voltage fields operate upon the mirror in complementary fashion.

13. The MEMS device of claim 7 wherein said spacer posts are conductive, enabling applying electrical signals from the MEMS device to the transparent electrodes.

14. The MEMS device of claim 13 wherein the substrate is invertedly flip-chip bonded to the device.

15. In an optical and electrical MEMS device carrying an electrical signal-orientable mirror suspended within a well in the device and wherein the device is physically and electrically integrally overlaid by an optically transmissive substrate carrying a pattern of printed electrical circuit interconnections but with sufficient upper clearance between the substrate and the mirror to avoid interference with the operation of the mirror as it is signal oriented by the field within the well, a method of supplementing electrical signal field control of the mirror, that comprises, providing transparent electrodes on the substrate in the region where it overlies the well and mirror, and applying voltage by said transparent electrodes to generate an upper electrical field above the mirror and well to supplement the signal orienting the mirror.

16. The method of claim 15 wherein the mirror is torsion-spring mounted within the well and is orientable in response to both the upper and lower electrical fields.

17. The method of claim 16 wherein the electrical fields are operated in complementary fashion.

18. The method of claim 16 wherein the MEMS device is orientable together with a plurality of successive similar MEMS devices to operate as an array of signal-orientable mirrors in response to optical addressing through the respective optically transmissive substrates of the devices.