Digital micromirror shutter device

• US 5,226,099 A
• Filed: 04/26/1991
• Issued: 07/06/1993
• Est. Priority Date: 04/26/1991
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Sampsell, Jeffrey B., Boysel, R. Mark, Mignardi, Michael A.
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): BARNS, STEPHEN
• Application Number:
  US07/691,920
• Time in Patent Office: 802 Days
• Field of Search: 385/13, 385/16, 385/19, 385/15, 385/39, 385/40, 385/25, 29/739, 29/740, 359/198, 359/199, 359/212
• US Class Current: 385/19
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 6/353 the optical element being a shutter, baffle, beam dump or opaque element absorbers on light guide termination G02B6/243
• CPC Class Codes: G02B 6/3552 1x1 switch, e.g. on/off switch
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/3596 With planar waveguide arrangement, i.e. in a substrate, regardless if actuating mechanism is outside the substrate

Abstract

There is disclosed a device that consists of a micro-mechanical switch consisting of an electrode, a gap between the electrode and an individually deflectable element, which has a vertical shutter attached to its underside. When the electrode is addressed the movement of the deflectable element causes the shutter to raise or lower. Such a device can be used in switching. One embodiment of such a use in waveguides is disclosed along with the method of manufacture.

Claims

1. A deflectable device comprising:

a. a substrate;

b. an electrode formed upon said substrate;

c. at least one support structure formed upon said substrate next to said electrode;

d. a movable metal element monolithically fabricated in conjunction with said electrode and said at least one support structure attached to said support structure above said electrode;

e. an air gap between said electrode and said element; and

f. a vertical structure attached to said element such that said vertical structure is in direct contact with said metal element.

2. The device of claim 1 wherein said substrate is silicon.

3. The device of claim 1 wherein said substrate is gallium arsenide.

4. The device of claim 1 wherein said electrode is metal.

5. The device of claim 1 wherein said electrode is polysilicon.

6. The device of claim 1 wherein said support structure comprises a metal post.

7. The device of claim 1 wherein said support structure comprises organic polymer.

8. The device of claim 1 wherein said metal element is attached to said support structure by one hinge.

9. The device of claim 1 wherein said metal element is attached to said support structure by two hinges.

10. The device of claim 1 wherein said metal element is attached to said support structure by four hinges.

11. A method of manufacture comprising:

a. forming electrodes upon a substrate;

b. coating said electrodes with a polymer spacer;

c. patterning said spacer;

d. forming metal layers upon said spacer;

e. patterning said metal layers to form hinges, metal elements and structure vertically attached to the underside of said metal elements;

f. dividing said substrate into individual devices;

g. removing a portion of said spacer from said devices; and

h. packaging said individual devices.

12. The method of claim 11 wherein said forming electrodes step comprises depositing, patterning and etching metal.

13. The method of claim 11 where said forming electrodes step comprises diffusing in a material to act as an electrode.

14. The method of claim 11 wherein said forming electrodes step comprises forming said electrodes out of polysilicon.

15. The method of claim 11 wherein said patterning said spacer layer comprises patterning said spacer with partial vias.

16. The method of claim 11 wherein said forming a metal layer step comprises depositing metal upon said spacer.

17. The method of claim 11 wherein said forming a metal layer step comprises patterning said spacer with vias prior to depositing said metal upon said spacer.

18. The method of claim 11 wherein said dividing step comprises sawing said wafer.

19. The method of claim 11 wherein said removing step comprises removing substantially all of said spacer.

20. The method of claim 11 wherein said removing step comprises removing a portion of said spacer and leaving a portion of said spacer to act as a support structure.

21. A deflectable device comprising:

a. a substrate;

b. a lower sheath upon said substrate;

c. a waveguide core upon said lower sheath;

d. an upper sheath upon said waveguide core;

e. a deflectable, monolithically fabricated metal element structure comprising a metal element and a vertical structure attached to said metal element such that said vertical structure is in direct contact with said metal element, said structure suspended over said waveguide core, separated from said core by an air gap; and

f. an electrode located adjacent said air gap for electrically addressing said metal element.

22. The device of claim 21 wherein said substrate is silicon.

23. The device of claim 21 wherein said lower sheath is silicon dioxide.

24. The device of claim 21 wherein said waveguide core is silicon nitride.

25. The device of claim 21 wherein said upper sheath is silicon dioxide.

26. A method of manufacture comprising:

a. forming electrodes upon a substrate;

b. coating said electrodes with a polymer spacer;

c. forming metal layers upon said spacer;

d. patterning said metal layers to form hinges, and metal elements;

e. forming a metal shutter layer upon said metal layers;

f. patterning said shutter layer;

g. removing portions of said shutter layer and said metal layers;

h. dividing said substrate into individual devices;

i. removing a portion of said spacer from said devices; and

j. packaging said individual devices.

27. The method of claim 26 wherein said forming electrodes step comprises depositing, patterning and etching metal.

28. The method of claim 26 where said forming electrodes step comprises diffusing in a material to act as an electrode.

29. The method of claim 26 wherein said forming electrodes step comprises forming said electrodes out of polysilicon.

30. The method of claim 26 wherein said forming a metal layer step comprises depositing metal upon said spacer.

31. The method of claim 26 wherein said forming a metal layer step comprises patterning said spacer with vias prior to depositing said metal layer upon said spacer.

32. The method of claim 26 wherein said patterning said metal layer comprises masking said metal layers.

33. The method of claim 26 wherein said forming said shutter metal layer comprises depositing said shutter layer upon said metal layers.

34. The method of claim 26 wherein said patterning said shutter layer comprises masking said shutter layer.

35. The method of claim 26 wherein said removing portions of said shutter layer and metal layers step comprises etching said layers.

36. The method of claim 26 wherein said dividing step comprises sawing said wafer.

37. The method of claim 26 wherein said removing step comprises removing substantially all of said spacer.

38. The method of claim 26 wherein said removing step comprises removing a portion of said spacer and leaving a portion of said spacer to act as a support structure.