Movable MEMS-based noncontacting device

• US 7,030,537 B2
• Filed: 03/01/2004
• Issued: 04/18/2006
• Est. Priority Date: 07/03/2001
• Status: Expired due to Fees

• Current Assignee: Altera Corporation (Intel Corporation)
• Original Assignee: Network Photonics, Inc.
• Inventors: Staple, Bevan, Roth, Richard
• Primary Examiner(s): TAMAI, KARL I
• Application Number:
  US10/791,633
• Publication Number:
  US 20040223686A1
• Time in Patent Office: 778 Days
• Field of Search: 310/309, 385 16- 24, 385/40, 385/47, 359223-226
• US Class Current: 310/309
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 3/0008 Structures for avoiding electrostatic attraction, e.g. avoiding charge accumulation
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3548 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3558 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system

Abstract

A microstructure for steering light that mitigates stiction problems is provided. A first tiltable assembly that includes a reflective coating is connected with a substrate. A second tiltable assembly is also connected with the substrate. First hand second electrodes are connected with the substrate and are configured to tilt the two tiltable assemblies such that they are interdigitated. In various embodiments, the tiltable assemblies are configured as cantilever arrangements and/or torsion-beam arrangements.

Claims

1. A movable microstructure comprising:

a first tiltable assembly formed over a substrate;

a second tiltable assembly formed over the substrate; and

first and second electrodes respectively positioned relative to the substrate to tilt the first and second tiltable assemblies upon activation such that the first and second tiltable assemblies become interdigitated and substantially coplanar.

2. The microstructure recited in claim 1 wherein the first tiltable assembly is configured as a cantilever arrangement.

3. The microstructure recited in claim 2 wherein the second tiltable assembly is configured as a torsion-beam arrangement.

4. The microstructure recited in claim 1 wherein the second tiltable assembly is configured as a torsion-beam arrangement.

5. The micro structure recited in claim 1,

wherein the first tiltable assembly includes:

a first structural linkage formed over the substrate;

a first structural film supported by the first structural linkage and having a plurality of fingers at an end of the first structural film; and

wherein the second tiltable assembly includes;

a second structural linkage formed over the substrate; and

a second structural film supported by the second structural linkage and having a plurality of fingers at an end of the second structural film.

6. The microstructure recited in claim 5 wherein the first and second electrodes comprise polysilicon.

7. The microstructure recited in claim 5 wherein the first and second structural films comprise polysilicon.

8. The microstructure recited in claim 5 wherein the first structural linkage has a greater height above the substrate than the second structural linkage.

9. A method for fabricating a movable microstructure, the method comprising:

forming a first tiltable assembly over a substrate;

forming a second tiltable assembly over the substrate; and

forming first and second electrodes relative to the substrate to tilt the first and second tiltable assemblies upon activation such that the first and second tiltable assemblies become interdigitated and substantially coplanar.

10. The method recited in claim 9 wherein forming the first tiltable assembly comprises creating a cantilever arrangement.

11. The method recited in claim 10 wherein forming the second tiltable assembly comprises creating a torsion-beam arrangement.

12. The method recited in claim 9 wherein forming the second tiltable assembly comprises creating a torsion-beam arrangement.

13. The method recited in claim 9,

wherein forming the first tiltable assembly includes:

forming a first structural linkage over the substrate;

forming a first structural film on the first structural linkage, the first structural film having a plurality of fingers at an end of the first structural film; and

wherein forming the second tiltable assembly includes;

forming a second structural linkage over the substrate; and

forming a second structural film on the second structural linkage, the second structural film having a plurality of fingers at an end of the second structural film.

14. The method recited in claim 13 wherein forming the first structural linkage comprises forming the first structural linkage over the substrate at a height greater than the second structural linkage.

15. A movable microstructure, the microstructure comprising:

first tiltable means formed over a support means;

second tiltable means formed over the support means; and

means for generating electrostatic forces for tilting the first tiltable means and the second tiltable means into an interdigitated and substantially coplanar configuration.

16. The microstructure recited in claim 15 wherein the first tiltable means comprises cantilever means.

17. The microstructure recited in claim 16 wherein the second tiltable means comprises torsion-beam means.

18. The microstructure recited in claim 15 wherein the second tiltable means comprises torsion-beam means.