METHOD AND SYSTEM FOR OPTICAL MEMS WITH FLEXIBLE LANDING STRUCTURES

• US 20090231671A1
• Filed: 02/14/2008
• Published: 09/17/2009
• Est. Priority Date: 02/14/2008
• Status: Active Grant

• Current Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Original Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Inventors: Payne, Justin, Wang, Yuxiang, Yang, Xiao, Wang, Ye, Ji, Wook
• Granted Patent: US 8,314,984 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
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An optical deflection device for a display application includes a semiconductor substrate comprising an upper surface region defining an upper surface plane. The optical deflection device also includes one or more electrode devices provided overlying the upper surface region and a hinge device including a silicon material and coupled to the upper surface region at a predetermined height above the upper surface plane. The optical deflection device further comprises a plurality of landing pads including a silicon material and coupled to the upper surface region at the predetermined height from the upper surface plane and a mirror structure. The mirror structure includes a post portion coupled to the hinge device and a mirror plate portion coupled to the post portion.

Claims

1. An optical deflection device for a display application, the optical deflection device comprising:

a semiconductor substrate comprising an upper surface region defining an upper surface plane;

one or more electrode devices provided overlying the upper surface region;

a hinge device comprising a silicon material and coupled to the upper surface region at a predetermined height above the upper surface plane;

a plurality of landing pads comprising a silicon material and coupled to the upper surface region at the predetermined height from the upper surface plane; and

a mirror structure comprising;

a post portion coupled to the hinge device, and

a mirror plate portion coupled to the post portion.

2. The optical deflection device of claim 1 wherein a lower side of the mirror plate portion is configured to make contact with one of the plurality of landing pads in a first activated position.

3. The optical deflection device of claim 2 wherein the lower side of the mirror plate portion comprises a corner region of the mirror plate portion.

4. The optical deflection device of claim 2 wherein a lower side of the mirror plate portion is configured to make contact with another of the plurality of landing pads in a second activated position.

5. The optical deflection device of claim 2 wherein the one of the plurality of landing pads deforms in response to the contact.

6. The optical deflection device of claim 1 wherein a thickness of the hinge device and a thickness of the plurality of landing pads are defined by a same thickness.

7. The optical deflection device of claim 1 wherein the silicon material comprises single crystal silicon.

8. The optical deflection device of claim 1 wherein the semiconductor substrate comprises a CMOS substrate.

9. The optical deflection device of claim 1 wherein the mirror structure comprises a silicon material.

10. The optical deflection device of claim 9 wherein the silicon material of the mirror structure comprises at least one of amorphous silicon, a polysilicon, or a silicon/metal alloy.

11. An array of optical deflection devices for a display application, the array of optical deflection devices comprising:

a semiconductor substrate comprising an upper surface region defining an upper surface plane;

a plurality of sets of electrode devices arrayed over the upper surface region;

a plurality of hinge devices, each of the plurality of hinge devices being associated with a set of electrode devices, wherein each of the plurality of hinge devices comprises a silicon material coupled to the upper surface region and positioned at a predetermined height above the upper surface plane;

a plurality of mirror structures, each of the plurality of mirror structures being joined to one of the plurality of hinge devices, wherein each of the plurality of mirror structures comprises;

a mirror anchor portion coupled to the one of the plurality of hinge devices, and

a mirror plate portion coupled to the mirror anchor portion; and

a plurality of sets of landing pads, each of the sets of landing pads being associated with one of the plurality of mirror structures, wherein each of the sets of landing pads comprises a silicon material coupled to the upper surface region at the predetermined height from the upper surface region.

12. The array of optical deflection devices of claim 11 wherein a lower side of the mirror plate portion is configured to make contact with a portion of a landing pad of the set of landing pads in a first activated position.

13. The array of optical deflection devices of claim 12 wherein the lower side of the mirror plate portion comprises a corner region of the mirror plate portion.

14. The array of optical deflection devices of claim 11 wherein the silicon material comprises single crystal silicon.

15. The array of optical deflection devices of claim 11 wherein the semiconductor substrate comprises a CMOS substrate.

16. The array of optical deflection devices of claim 11 wherein the mirror structure comprises a silicon material.

17. The array of optical deflection devices of claim 16 wherein the silicon material of the mirror structure comprises at least one of amorphous silicon, a polysilicon, or a silicon/metal alloy.

18. A method of fabricating an optical deflection device, the method comprising:

providing a substrate;

forming a planarized dielectric layer over the substrate;

forming a plurality of cavities in the planarized dielectric layer;

performing a layer transfer process to bond a silicon layer to the planarized dielectric layer;

forming a hinge and a plurality of landing pads from the silicon layer;

forming a substantially planarized material layer coupled to the hinge;

forming a mirror anchor cavity in the substantially planarized material layer;

forming a mirror structure filling at least a portion of the mirror anchor cavity; and

releasing the mirror structure.

19. The method of claim 18 wherein forming the plurality of landing pads from the silicon layer comprises forming one or more recesses passing through a thickness of the plurality of landing pads.

20. The method of claim 18 wherein the mirror structure comprises a silicon mirror structure.

21. The method of claim 20 wherein the silicon layer comprises a single crystal silicon layer.

22. The method of claim 18 further comprising forming a metal layer coupled to the silicon layer.

23. The method of claim 18 wherein the layer transfer process comprises a substrate bonding process.

24. The method of claim 18 wherein forming the mirror structure comprises depositing and planarizing at least one of an amorphous silicon layer, a polysilicon layer, or a silicon/metal alloy.

25. The method of claim 18 wherein the plurality of cavities comprise a first cavity associated with the hinge and a second set of cavities associated with the plurality of landing pads.