METHOD AND APPARATUS FOR A REFLECTIVE SPATIAL LIGHT MODULATOR WITH A FLEXIBLE PEDESTAL

• US 20080055709A1
• Filed: 05/23/2007
• Published: 03/06/2008
• Est. Priority Date: 07/28/2004
• Status: Active Grant

• Current Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Original Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Inventors: Yang, Xiao
• Granted Patent: US 7,570,416 B2
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

An electromechanical system comprising a substrate including a surface region and a flexible member coupled at a first end to the surface region. The system further comprises a base region and a tip region. The system also comprises a reflective member coupled to the flexible member, including a reflective surface and a backside region, the backside region being coupled to the second end of the flexible member, the reflective surface being substantially parallel to the surface region while the reflective member is in a first state and being substantially non-parallel to the surface region while the reflective member is in a second state. The flexible member moves from a first position characterized by the first state to a second position characterized by the second state and the angle between the first state and the second state is greater than 12°.

Claims

1. An electromechanical system disposed in an array configuration, the electromechanical system comprising:

a substrate comprising a surface region including an array of electrodes, each of the array of electrodes being provided in pairs and configured to support a first voltage and a second voltage different from the first voltage; and

an array of moveable structures, each of the array of moveable structures being associated with a pair of electrodes of the array of electrodes, each of the array of moveable structures including;

a flexible member comprising a first end coupled to the surface region of the substrate and a second end opposing the first end, wherein a length is defined between the first end and the second end;

a base region within a first portion of the flexible member, the base region being defined from the first end to a first predetermined portion of the length of the flexible member;

a tip region within a second portion of the flexible member, the tip region being defined from the second end to a second predetermined portion of the length of the flexible member; and

a moveable surface coupled to the flexible member and comprising a frontside region and a backside region, the backside region being coupled to the second end of the flexible member, wherein a normal of the frontside region is configured to be oriented at a first angle with respect to the surface region in response to the first voltage and oriented at a second angle with respect to the surface region in response to the second voltage.

2. The electromechanical system of claim 1 wherein:

the base region is characterized by at least a first cross-sectional area, the first cross-sectional area being substantially parallel to the surface region of the substrate; and

the tip region is characterized by at least a second cross-sectional area, the second cross-sectional area being substantially parallel to the surface region of the substrate and less than the first cross-sectional area.

3. The electromechanical system of claim 1 wherein the frontside region comprises a reflective surface.

4. The electromechanical system of claim 3 the reflective surface is disposed on a micro-mirror forming a portion of a micro-mirror array.

5. The electromechanical system of claim 4 wherein the micro-mirror array comprises a spatial light modulator.

6. The electromechanical system of claim 1 wherein the array of moveable structures comprises a single crystal silicon material.

7. The electromechanical system of claim 1 wherein the first angle with respect to the surface region and the second angle with respect to the surface region defined a plane.

8. The electromechanical system of claim 7 wherein movement of the flexible member in the plane results in a restoring torque orthogonal to the plane.

9. An electromechanical system disposed in an array configuration, the electromechanical system comprising:

a substrate comprising a surface region;

a set of electrodes disposed on the surface region and separated by a first distance to define a separation region, the set of electrodes configured to receive a first voltage and a second voltage;

a flexible member coupled at a first end to the surface region at a position between the set of electrodes in the separation region, wherein the flexible member comprises a second end and a length defined between the first end and the second end and wherein the flexible member comprises;

a base region disposed within a first portion of the flexible member, the base region being defined from the first end to a first predetermined portion of the length of the flexible member, the base region being characterized by a first rectangular cross-sectional area measured parallel to the surface region of the substrate;

a tip region within a second portion of the flexible member, the tip region being defined from the second end to a second predetermined portion of the length of the flexible member, the tip region being characterized by a at least a second rectangular cross-sectional area measured parallel to the surface region of the substrate; and

a moveable member coupled to the flexible member, the moveable member comprising a frontside surface and a backside surface, the backside surface being coupled to the second end of the flexible member, the moveable surface being substantially parallel to the surface region in a first state associated with the first voltage and being substantially non-parallel to the surface region in a second state associated with the second voltage.

10. The electromechanical system of claim 9 wherein the moveable member comprises a reflective surface.

11. The electromechanical system of claim 10 wherein at least a portion of the reflective surface has a reflectance greater than 95%.

12. The electromechanical system of claim 11 wherein the reflective surface comprises a micro-mirror forming a portion of a micro-mirror array.

13. The electromechanical system of claim 9 wherein the flexible member and the moveable member comprise a single crystal silicon material.

14. An array of moveable structures, the array comprising:

a substrate comprising a surface region;

a plurality of electrically activated electrodes coupled to the surface region of the substrate, the plurality of electrically activated electrodes being coupled to an electrical source to receive an electrical signal;

a plurality of flexible members comprising a first end coupled to the surface region of the first substrate and a second end with a length defined between the first end and the second end;

a base region within a first portion of each of the plurality of flexible members, the base region being defined from the first end to a first predetermined portion of the length of each of the plurality of flexible members, the base region being characterized by a rectangular cross-section having a base length and a base width less than the base length;

a tip region within a second portion of each of the plurality of flexible members, the tip region being defined from the second end to a second predetermined portion of the length of each of the plurality of flexible members, the tip region being characterized by a second rectangular cross-section having a tip length and tip width less than the tip length; and

a plurality of moveable structures, wherein each of the plurality of moveable structures is coupled to one of the plurality of flexible members and configured to overhang the one of the plurality of flexible members.

15. The array of moveable structures of claim 14 wherein the plurality of moveable structures comprises an array of micro-mirrors.

16. The array of moveable structures of claim 15 wherein a separation between an outer edge of a first micro-mirror of the array of micro-mirrors and an outer edge of a second micro-mirror of the array of micro-mirrors is less than 1 μ

m, the first micro-mirror being adjacent to the second micro-mirror in the array of micro-mirrors.

17. The array of moveable structures of claim 15 wherein a center-to-center spacing of the array of micro-mirrors is less than or equal to about 15 μ

m.

18. The array of moveable structures of claim 17 wherein a center-to-center spacing of the array of micro-mirrors is less than or equal to about 10 μ

m.

19. The array of moveable structures of claim 14 wherein the substrate comprises an array of memory cells, row address circuitry, and column data loading circuitry.

20. The array of moveable structures of claim 14 wherein a first area defined by a product of the base length and the base width is less greater than a second area defined by a product of the tip length and the tip width.