MECHANICAL LAYER AND METHODS OF SHAPING THE SAME

• US 20110235155A1
• Filed: 03/25/2010
• Published: 09/29/2011
• Est. Priority Date: 03/25/2010
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Sasagawa, Teruo, Tao, Yi, Zhong, Fan
• Granted Patent: US 8,547,626 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 3/0072 For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers
• 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
• CPC Class Codes: G02B 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

A method of shaping a mechanical layer is disclosed. In one embodiment, the method comprises depositing a support layer, a sacrificial layer and a mechanical layer over a substrate, and forming a support post from the support layer. A kink is formed adjacent to the support post in the mechanical layer. The kink comprises a rising edge and a falling edge, and the kink can be configured to control the shaping and curvature of the mechanical layer upon removal of the sacrificial layer.

Claims

1. An electromechanical systems device, comprising:

a substrate;

a mechanical layer having an actuated position and a relaxed position; and

a support structure on the substrate for supporting the mechanical layer, wherein the support structure is configured to space the mechanical layer from the substrate to define a collapsible gap, wherein the gap is in a collapsed condition when the mechanical layer is in the actuated position and in a non-collapsed condition when the mechanical layer is in the relaxed position,

wherein the mechanical layer comprises a kink adjacent to the support structure, wherein the kink comprises a rising portion and a falling portion, wherein the rising portion extends away from the gap and the falling portion extends toward the gap.

2. The electromechanical systems device of claim 1 wherein the kink is spaced from the support structure by less than about 5 μ

m.

3. The electromechanical systems device of claim 2 further comprising a stationary electrode positioned between the substrate and the collapsible gap.

4. The electromechanical systems device of claim 3, wherein the stationary electrode is an optical stack.

5. The electromechanical systems device of claim 3 wherein the mechanical layer further comprises a bottom reflective surface facing the gap, and wherein the optical stack and the bottom reflective surface of the mechanical layer form an interferometric modulator.

6. The electromechanical systems device of claim 5 further comprising a bias circuit configured to apply a bias voltage, wherein when the bias voltage is applied at least a portion of the mechanical layer is substantially parallel to the substrate.

7. The electromechanical systems device of claim 2 wherein the kink extends away from the substrate.

8. The electromechanical systems device of claim 7 wherein the kink divides the mechanical layer into a first portion and a second portion, wherein the first portion is positioned between the support structure and the rising portion of the kink, and wherein thicknesses of the mechanical layer along the rising portion, the falling portion, the first portion, and the second portion are substantially equal.

9. The electromechanical systems device of claim 8 wherein the rising portion of the kink is spaced from the falling portions of the kink by a width of less than about 5 μ

m.

10. The electromechanical systems device of claim 8 wherein the rising portion contacts the first portion at a first juncture and the falling portion contacts the second portion at a second juncture, wherein a line drawn through the first juncture and the second juncture is substantially parallel to the first portion and the second portion when the mechanical layer is in the relaxed position.

11. The electromechanical systems device of claim 2 wherein a first portion of the kink is elongated along a first side of the support structure, the first side being along the perimeter of the support structure.

12. The electromechanical systems device of claim 11 further comprising one or more additional kinks, wherein the kink and the one or more additional kinks surround greater than about 25 percent of the perimeter of the support structure.

13. The electromechanical systems device of claim 11 wherein the kink comprises a closed shape, wherein a side of the closed shape is substantially parallel to the first side of the support structure in contact with the mechanical layer.

14. The electromechanical systems device of claim 2, wherein the mechanical layer comprises a first conductive layer, a second conductive layer, and a supporting layer, wherein the supporting layer is positioned between the first and second conductive layers.

15. The electromechanical systems device of claim 2 wherein the kink extends toward the substrate.

16. The apparatus of claim 1, further comprising:

a display;

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

a memory device that is configured to communicate with said processor.

17. The apparatus as recited in claim 16, further comprising:

a driver circuit configured to send at least one signal to said display.

18. The apparatus as recited in claim 17, further comprising:

a controller configured to send at least a portion of said image data to said driver circuit.

19. The apparatus as recited in claim 18, further comprising:

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

20. The electromechanical systems device of claim 1 wherein the kink is spaced from the support structure by less than a width of the support structure.

21. An electromechanical systems device, comprising:

a substrate means;

a deformable means having a relaxed and an actuated position; and

a support means for supporting the deformable means and for spacing the deformable means from the substrate by a collapsible gap, wherein the collapsible gap is in a collapsed condition when the deformable means is in the actuated position and in a non-collapsed condition when the deformable means is in the relaxed position,

wherein the deformable means comprises a shaping means for directing curvature of the deformable means.

22. The electromechanical systems device of claim 21 wherein the shaping means is spaced from the support means by less than about 5 μ

m.

23. The electromechanical systems device of claim 21 wherein the shaping means is spaced from the support means by less than a width of the support means.

24. The electromechanical systems device of claim 21 wherein the shaping means is adapted to direct the curvature of the deformable means away from the substrate means when the deformable means is in the relaxed position.

25. The electromechanical systems device of claim 21 wherein the shaping means includes an elongated rail extending along a side of the support means, the side being along the perimeter of the support means.

26. The electromechanical systems device of claim 25 wherein the shaping means includes a kink extending away from the substrate.

27. The electromechanical systems device of claim 21 further comprising a fixed electrode positioned between the substrate means and the collapsible gap and a bias means for applying a bias voltage between the fixed electrode and the deformable means, wherein the shaping means is further configured for ensuring flatness of at least a portion of the deformable means when the bias voltage is applied.

28. A method of shaping a mechanical layer in an electromechanical systems device, comprising:

providing a substrate;

depositing a support layer over at least a portion of the substrate;

forming a support post from at least the support layer;

providing a mechanical layer with a kink adjacent to the support post, wherein the kink comprises a rising edge and a falling edge; and

supporting the mechanical layer with the support post to define a collapsible gap over the substrate.

29. The method of claim 28 wherein providing the mechanical layer with the kink comprising depositing a shaping layer over at least a portion of the substrate, wherein the geometry of the shaping layer is configured so that a protrusion is formed, and wherein providing the mechanical layer with the kink further comprises depositing a conformal mechanical layer over the protrusion so that when the mechanical layer is deposited, the kink is formed in the mechanical layer over the protrusion.

30. The method of claim 29 further comprising depositing a black mask over at least a portion of the substrate, and wherein a portion of the shaping layer and a portion of the black mask are configured to overlap so as to form the protrusion.

31. The method of claim 29 wherein the protrusion comprises the portion of the black mask over the portion of the shaping layer.

32. The method of claim 29 wherein the protrusion comprises the portion of the shaping layer over the portion of the black mask.

33. The method of claim 29 further comprising:

depositing a sacrificial layer adjacent to the support layer and over at least a portion of the shaping layer and the black mask, wherein the step of depositing the sacrificial layer is performed before depositing the mechanical layer; and

removing the sacrificial layer.