PERIODIC DIMPLE ARRAY

• US 20100309572A1
• Filed: 07/29/2010
• Published: 12/09/2010
• Est. Priority Date: 09/14/2007
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Mignard, Marc Maurice
• Application Number:
  US12/846,401
• Publication Number:
  US 20100309572A1
• Time in Patent Office: Days
• US Class Current: 359/883
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81C 1/0019 Flexible or deformable structures not provided for in groups B81C1/00142 - B81C1/00182
• 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 26/0825 the reflecting element being a flexible sheet or membrane, e.g. for varying the focus flexible mirrors for cosmetic use A45D42/24
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A microelectromechanical (MEMS) device includes a substrate, an actuation electrode over the substrate, a reflective layer over the actuation electrode, and a support layer between the actuation electrode and the reflective layer. The reflective layer includes at least one aperture through the reflective layer. The support layer includes a recess between the actuation electrode and the at least one aperture. Upon application of a control signal to the device, at least a first portion of the reflective layer is configured to move into the recess and at least a second portion of the reflective layer is configured to remain stationary. The reflectivity of the MEMS device is dominantly modulated by changing a phase difference between light reflected from the first portion and light reflected from the second portion.

Claims

1. A reflective surface for presenting an image to a viewer, the reflective surface comprising:

a base layer comprising a first region having a plurality of recesses in a surface of the base layer, each of the recesses having a width of less than about 1 μ

m, wherein adjacent said recesses are in a pattern that is periodic in two dimensions and have a center-to-center distance less than about 2 μ

m, the recesses extending into the base layer to a first depth; and

a reflective layer over the base layer, the reflective layer comprising a first portion disposed over the first region within the recesses, the reflective layer further comprising a second portion disposed over the first region between the recesses,

wherein a ratio of an area of the reflective layer first portion to an area of the reflective layer second portion is less than about 1;

1.

2. The reflective surface of claim 1, wherein the base layer further comprises a second region comprising a third portion substantially devoid of recesses, and wherein the reflective layer comprises a third portion disposed over the second region.

3. The reflective surface of claim 1, wherein the base layer further comprises a second region having a plurality of second recesses in the surface of the base layer, each of the second recesses having a width of less than about 1 μ

m, adjacent said second recesses in a pattern that is periodic in two dimensions, adjacent said second recesses having a center-to-center distance less than about 2 μ

m, the second recesses extending into the base layer to second depth that is different than the first depth, and wherein the reflective layer comprises a third portion and a fourth portion, the third portion disposed over the second region and within the second recesses, the fourth portion disposed over the second region between the second recesses, wherein a ratio of an area of the third portion to an area of the fourth portion is less than about 1;

1.

4. The reflective surface of claim 1, wherein each of the recesses has a width of between about 30 nm and about 1 μ

m.

5. The reflective surface of claim 1, wherein the base layer comprises at least one of plastic, glass, and a semiconductor.

6. The reflective surface of claim 1, wherein the reflective surface is flexible.

7. A reflective surface for presenting an image to a viewer, the reflective surface comprising:

a base layer comprising a first region and a second region, the base layer having a surface;

a plurality of first recesses in the surface of first region of the base layer, the first recesses having a first depth that extends into the surface of the base layer;

a plurality of second recesses in the surface of second region of the base layer, the second recesses having a second depth that extends into the surface of the base layer, the second depth being different than the first depth; and

a reflective layer disposed over the base layer, the reflective layer comprising

a first portion of the reflective layer disposed over the first region and within the first recesses;

a second portion of the reflective layer disposed over the first region between the first recesses and not within the first recesses, wherein a ratio of an area of the first portion to an area of the second portion is less than about 1;

1; and

a third portion of the reflective layer disposed over the second region.

8. The reflective surface of claim 7, wherein the third portion of the reflective layer is within the second recesses, and wherein the reflective layer comprises a fourth portiondisposed over the second region, between the second recesses, and not within the second recesses, wherein a ratio of an area of the third portion to an area of the fourth portion is less than about 1:

1.

9. The reflective surface of claim 7, wherein each of the recesses has a width of between about 30 nm and about 1 μ

m.

10. The reflective surface of claim 7, wherein the base layer comprises at least one of plastic, glass, and a semiconductor.

11. The reflective surface of claim 7, wherein the reflective surface is flexible.

12. A method of forming a reflective surface, the method comprising:

forming a first region comprising forming a plurality of recesses in a surface of a base layer, each of the recesses having a width of less than about 1 μ

m, wherein adjacent said recesses are in a pattern that is periodic in two dimensions along the base layer, wherein adjacent said recesses have a center-to-center distance less than about 2 μ

m, the recesses having a depth into the surface of the base layer; and

depositing a layer of reflective material over the base layer, the reflective layer comprising a first portion and a second portion, the first portion over the first region and within the recesses, the second portion over the first region, between the recesses, and not within the recesses, a ratio of an area of the first portion to an area of the second portion less than about 1;

1.

13. The method of claim 12, wherein forming the recesses in the base layer comprises embossing.

14. The method of claim 13, wherein embossing the recesses comprises:

forming a die including a negative impression of the recesses; and

imprinting the base layer of with the die.

15. The method of claim 12, wherein forming the recesses in the base layer comprises reactive ion etching.

16. The method of claim 12, wherein forming the recesses in the base layer comprises direct patterning using a focused ion beam.

17. The method of claim 12, wherein depositing the layer of reflective material comprises at least one of sputtering, plating, and chemical vapor depositing.

18. The method of claim 12, further comprising depositing a layer of reflective material over a second region of the base layer substantially devoid of recesses, the reflective layer comprising a third portion over the second region.

19. The method of claim 12, further comprising:

forming a second region comprising forming a plurality of second recesses in the surface of the base layer, each of the second recesses having a width of less than about 1 μ

m, wherein adjacent said second recesses are in a pattern that is periodic in two dimensions along the base layer, wherein adjacent said second recesses have a center-to-center distance less than about 2 μ

m, the second recesses having a second depth into the surface of the base layer different than the depth of the recesses of the first region; and

depositing a layer of reflective material over the second region, the reflective layer comprising a third portion and a fourth portion, the third portion over the second region and within the second recesses, the fourth portion over the second region, between the second recesses, and not within the second recesses, a ratio of an area of the first third to an area of the fourth portion less than about 1;

1.

20. The method of claim 12, wherein the reflective surface is flexible.