MEMS device fabricated on a pre-patterned substrate

• US 20060067646A1
• Filed: 07/01/2005
• Published: 03/30/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Chui, Clarence
• Granted Patent: US 7,373,026 B2
• Time in Patent Office: Days
• US Class Current: 385/147
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

A microelectromechanical systems device fabricated on a pre-patterned substrate having grooves formed therein. A lower electrode is deposited over the substrate and separated by an orthogonal upper electrode by a cavity. The upper electrode is configured to be movable to modulate reflected light. A semi-reflective layer and a transparent material are formed over the movable upper electrode.

Claims

1. A method of making a microelectromechanical systems device, comprising:

providing a substrate having a plurality of trenches;

depositing at least one layer over the substrate, wherein the layer is discontinuous at the trenches; and

creating a first cavity between a first electrode formed over the substrate and a second electrode, wherein the at least one layer comprises the first electrode.

2. The method of claim 1, further comprising insulating the first electrode from the second electrode.

3. The method of claim 2, wherein insulating comprises depositing a dielectric material over the first electrode.

4. The method of claim 3, wherein the first cavity is created by depositing a sacrificial material over the dielectric material prior to forming the second electrode and removing the sacrificial material after forming the second electrode.

5. The method of claim 1, further comprising creating a second cavity between the second electrode and a semi-reflective layer.

6. The method of claim 5, wherein creating the second cavity comprises depositing a sacrificial material over the second electrode prior to forming the semi-reflective layer and removing the sacrificial material after forming the semi-reflective layer.

7. The method of claim 5, wherein the semi-reflective layer comprises chromium.

8. The method of claim 5, further comprising depositing a transparent material over the semi-reflective layer.

9. The method of claim 8, wherein creating the first cavity comprises depositing a sacrificial material over the dielectric material prior to forming the second electrode and removing the sacrificial material after forming the second electrode.

10. The method of claim 9, wherein the transparent material and semi-reflective layer are etched with openings prior to removing the first sacrificial layer.

11. The method of claim 1, wherein providing comprises embossing the trenches in the substrate.

12. The method of claim 1, wherein providing comprises ablating the trenches in the substrate.

13. The method of claim 1, wherein providing comprises forming the trenches in the substrate by a molding process.

14. The method of claim 1, wherein the at least one layer includes a conductive layer and the discontinuity of the layer at the trenches patterns the first electrode.

15. The method of claim 1, wherein the microelectromechanical systems device is an interferometric modulator.

16. A microelectromechanical systems device formed by the method of claim 1.

17. A display device, comprising:

a substrate embossed having a plurality of grooves formed therein;

a first electrode formed over a top surface of the substrate and a second electrode, wherein the first electrode and the second electrode are insulated from each other and separated by a first cavity;

a semi-reflective layer separated from the second electrode by a second cavity; and

a transparent material formed over the semi-reflective layer.

18. The display device of claim 17, wherein the first and second electrodes are insulated from each other by a dielectric material deposited over the first electrode.

19. The display device of claim 17, wherein the transparent material has a plurality of holes formed therein.

20. The display device of claim 17, wherein each of the plurality of grooves has a reentrant profile.

21. The display device of claim 17, wherein the substrate is opaque.

22. The display device of claim 17, wherein the first electrode is orthogonal to the second electrode.

23. The display device of claim 17, wherein the second electrode is configured to be movable.

24. The display device of claim 23, wherein the second cavity is larger and the first cavity is smaller when the second electrode is moved.

25. The display device of claim 17, further comprising:

a display;

a processor that is in electrical communication with said display, said processor being configured to process image data; and

a memory device in electrical communication with said processor

26. The display device of claim 25, further comprising:

a first controller configured to send at least one signal to said display; and

a second controller configured to send at least a portion of said image data to said first controller.

27. The display system as recited in claim 25, further comprising:

an image source module configured to send said image data to said processor.

28. The display system as recited in claim 27, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

29. The display system as recited in claim 25, further comprising:

an input device configured to receive input data and to communicate said input data to said processor.

30. A method of forming a microelectromechanical systems device, comprising:

providing a substrate having a top surface, wherein a plurality of grooves is formed in the top surface;

depositing at least one layer over the substrate, wherein the at least one layer comprises a first conductive material and is discontinuous at the grooves forming rows of the layer between the grooves on the top surface; and

depositing a second conductive material, wherein the second conductive material is oriented orthogonally to the first conductive material on the top surface.

31. The method of claim 30, wherein the at least one layer further comprises a dielectric layer and a sacrificial material.

32. The method of claim 30, further comprising creating a first cavity between the first conductive material and the second conductive material.

33. The method of claim 31, further comprising depositing a semi-reflective layer over the second conductive material, wherein the semi-reflective layer and the second conductive material are separated by a cavity.

34. The method of claim 32, wherein the cavity between the chromium layer and the second conductive material is created by removing a sacrificial material between the semi-reflective layer and the second conductive material.

35. The method of claim 30, wherein providing the plurality of grooves in the top surface comprises embossing.

36. The method of claim 35, further comprising baking the substrate after embossing to provide each of the grooves with a reentrant profile, wherein the substrate is formed of a composite material.

37. The method of claim 36, wherein a top layer of the composite material has a higher coefficient of thermal expansion than that of a lower layer of the composite material.

38. A display device, comprising

a substrate having a plurality of grooves formed therein;

a first reflecting means for reflecting light formed over a top surface of the substrate and a second reflecting means for reflecting light, wherein the first reflecting means and the second reflecting means are insulated from each other and separated by a first cavity;

a semi-reflective layer separated from the second reflecting means by a second cavity; and

a viewing means for transmitting light, the viewing means formed over the semi-reflective layer.

39. The display device of claim 38, wherein the first reflecting means on the top surface of the substrate is discontinuous at the grooves forming rows of the first reflecting means on the top surface.

40. The display device of claim 39, wherein the second reflecting means is oriented in rows orthogonally to the rows of the first reflecting means.

41. The display device of claim 39, wherein the first and second reflecting means are insulated from each other by a dielectric material deposited over the first reflecting means.

42. The display device of claim 39, wherein the second reflecting means is configured to be movable.