Micromirror device and method for making the same

• US 7,483,198 B2
• Filed: 02/11/2005
• Issued: 01/27/2009
• Est. Priority Date: 02/12/2003
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Zhang, Jianglong, Shi, Hongqin, Huibers, Andrew, Patel, Satyadev, Simonian, Dmitri, Dunphy, James, Doan, Jonathan
• Primary Examiner(s): Dang; Hung X
• Assistant Examiner(s): Tra; Tuyen Q
• Application Number:
  US11/056,752
• Publication Number:
  US 20050157375A1
• Time in Patent Office: 1,446 Days
• Field of Search: 359/291, 359/292, 359/293, 359/295, 359/298, 359/214, 359/220, 359/222, 359/223, 359/224, 359/230, 359/320, 359/322
• US Class Current: 359/291
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites

Abstract

Disclosed herein is a micromirror device having in-plane deformable hinge to which a deflectable and reflective mirror plate is attached. The mirror plate rotates to different angles in response to an electrostatic field established between the mirror plate and an addressing electrode associated with the mirror plate.

Claims

1. A spatial light modulator device, comprising:

an array of micromirror devices on a substrate, each of which comprises;

a reflective mirror plate;

a hinge to which the mirror plate is attached such that the mirror plate can move relative to the substrate, wherein the deformable hinge is positioned in a different plane than the mirror plate leaving a gap between the mirror plate and hinge in a direction perpendicular to the mirror plate when the mirror plate is not moved;

wherein the deformable hinge comprises single crystal silicon.

2. The device of claim 1, wherein the mirror plate is single crystal silicon.

3. The device claim 1, wherein the deformable hinge is single crystal silicon.

4. The device of claim 3, wherein the mirror plate is a thin film.

5. The device of claim 1, wherein both of the mirror plate and the deformable hinge are single crystal silicon.

6. The device of claim 1, further comprising:

an array of addressing electrodes, each of which is associated with mirror plate for deflecting said mirror plate.

7. The device of claim 1, wherein the mirror plate comprises a layer comprising aluminum for reflecting light.

8. The device of claim 7, wherein the mirror plate further comprises a barrier layer between a surface of the mirror plate and the aluminum.

9. The device of claim 8, wherein the barrier layer comprises TiN_x.

10. The device of claim 8, wherein the barrier layer comprises SiN_x.

11. The device of claim 8, wherein the barrier layer comprises SiO_x.

12. The device of claim 1, wherein the hinge comprises Si.

13. The device of claim 1, wherein the hinge is formed from a single crystal that is doped with a material that is a rare-earth element or a transition metal element.

14. The device of claim 1, wherein a center-to-center distance between adjacent micromirrors in the micromirror array is 10.16 microns or less.

15. The device of claim 14, wherein the center-to-center distance between adjacent micromirrors in the micromirror array is from 4.38 to 10.16 microns.

16. The device of claim 1, wherein the nearest distance between mirror plates of the adjacent micromirrors in the micromirror array is 0.5 micron or less.

17. The device of claim 1, wherein the nearest distance between mirror plates of the adjacent micromirrors in the micromirror array is from 0.1 to 0.5 micron.

18. The device of claim 1, wherein a vertical distance between the mirror plate and the deformable hinge is 0.45 micron or less.

19. The device of claim 1, wherein the vertical distance between the mirror plate and the deformable hinge is from 0.1 to 0.45 micron or less.

20. The device of claim 1, wherein the mirror plate has a thickness of 0.5 micron or less.

21. The device of claim 1, wherein the mirror plate is attached to the hinge such that the mirror plate is operable to rotate to a maximum angle in one direction larger than a maximum angle in another direction.

22. The device of claim 1, wherein the mirror plate is operable to rotate to an angle of 14°

degrees or more.

23. The device of claim 22, wherein the mirror plate is operable to rotate to an angle of 16°

degrees or more.

24. The device of claim 22, wherein the mirror plate is operable to rotate to an angle of 12°

degrees or more.

25. A projection system, comprising:

an illumination system providing illumination light for the system; and

a spatial light modulator of claim 1.

26. The projection system of claim 25, further comprising:

a condensing lens directing the illumination light onto the spatial light modulator.

27. The projection system of claim 25, further comprising:

a projection lens directing the illumination light from the spatial light modulator on to a display target.

28. The projection system of claim 25, wherein the illumination system further comprises:

a light course providing a white light beam; and

a lightpipe directing the white light beam to a color wheel, wherein the color wheel comprises a set of primary color segments that split the white light beam into a set of primary color light beams.

29. The projection system of claim 25, wherein the illumination system further comprises:

a light course providing a white light beam;

a color wheel comprising a set of primary color segments that split the white light beam into a set of primary color light beams; and

a lightpipe directing the primary color light beams onto the spatial light modulator.