Interferometric modulator mirror design without metal layer in the hinge

Patent metadata

Field	Value
Publication number	US-9715156-B2
Application number	US-201514662031-A
Country	US
Kind code	B2
Filing date	Mar 18, 2015
Priority date	Mar 18, 2015
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

Various implementations described herein involve interferometric modulators (IMODs), which may be single-mirror IMODs (SMIs). Such IMODs may include an absorber stack and a mirror stack. The absorber stack and the mirror stack may define a gap therebetween and may be capable of being positioned in a plurality of positions relative to one another to form a plurality of gap heights. A hinge area may physically connect the mirror stack and an anchor area. Some such IMODs have hinge areas without any metal layer. However, the hinge area may be capable of forming an electrical connection with at least one metal layer of the mirror stack. For example, such IMODs may have a hinge area that includes a non-metal conductor.

First claim

What is claimed is:

1. An interferometric modulator (IMOD), comprising:
a mirror stack including a first metal layer;
a substrate formed of substantially transparent material;
an absorber stack disposed on the substrate, the absorber stack including an absorber layer;
an anchor area including a plurality of anchors; and
a hinge area including at least one non-metal conductor, the hinge area having no metal layer, the hinge area attached to and physically connecting the mirror stack and the anchor area, the hinge area being configured for electrical connectivity with the first metal layer, wherein
the absorber stack and the mirror stack define a gap therebetween and are configured for being positioned in a plurality of positions relative to one another, to form a plurality of gap heights; and
each reflective color of a plurality of reflective colors of the IMOD corresponds with a gap height of the plurality of gap heights.

2. The IMOD of claim 1 , wherein the hinge area includes at least one material selected from a list of materials consisting of metal oxides and metal nitrides.

3. The IMOD of claim 1 , wherein the at least one non-metal conductor is selected from a list of non-metal conductors consisting of carbon, indium tin oxide, tantalum nitride, tantalum oxide, titanium oxide, titanium oxynitride and zirconium oxide.

4. The IMOD of claim 1 , wherein the plurality of reflective colors includes more than two colors.

5. The IMOD of claim 1 , wherein the mirror stack is configured for being actuated via electrical signals received by the first metal layer via the hinge area.

6. The IMOD of claim 1 , wherein the mirror stack further comprises:
a first dielectric layer proximate the first metal layer, the first dielectric layer having a first index of refraction; and
a second dielectric layer proximate the first dielectric layer, the second dielectric layer having a second index of refraction that is higher than the first index of refraction.

7. The IMOD of claim 6 , wherein the first metal layer is disposed proximate a first side of the mirror stack and wherein the mirror stack further comprises:
a second metal layer disposed proximate a second side of the mirror stack;
a third dielectric layer proximate the second metal layer, the third dielectric layer being formed of the same material as, and having a thickness substantially equal to that of, the first dielectric layer; and
a fourth dielectric layer proximate the third dielectric layer, the fourth dielectric layer being formed of the same material as, and having a thickness substantially equal to that of, the second dielectric layer.

8. The IMOD of claim 1 , further comprising a plurality of protrusions disposed on at least one of the absorber stack or the mirror stack, the protrusions being configured for preventing contact between areas of the mirror and areas of the absorber stack.

9. The IMOD of claim 8 , wherein each of the protrusions extends between 5 and 20 nm from the surface on which the protrusion is formed.

10. A display device that includes the IMOD of claim 1 , wherein the display device includes a control system configured for controlling each pixel of the display device independently and wherein the control system is configured for processing image data.

11. The display device of claim 10 , wherein the control system further comprises:
a plurality of thin-film transistor (TFT) switches, each of the plurality of TFT switches corresponding to an individual pixel of the display device.

12. The display device of claim 10 , wherein the control system further comprises:
an image source module configured for sending the image data to the processor, wherein the image source module includes at least one of a receiver, transceiver, and transmitter.

13. The display device of claim 10 , further comprising:
an input device configured for receiving input data and of communicating the input data to the control system.

14. The IMOD of claim 1 , further comprising:
an electrode; and
a control system configured for moving the mirror stack away from the absorber stack by applying a voltage between the electrode and the mirror stack.

15. An interferometric modulator (IMOD), comprising:
a mirror stack including a first metal layer;
a substrate formed of substantially transparent material;
an absorber stack disposed on the substrate, the absorber stack including an absorber layer, the absorber stack and the mirror stack defining a gap therebetween;
an anchor area including a plurality of anchors;
a hinge area including at least one non-metal conductor, the hinge area having no metal layer, the hinge area attached to and physically connecting the mirror stack and the anchor area, the hinge area being configured for electrical connectivity with the first metal layer; and
means for positioning the mirror stack in a plurality of positions relative to the absorber stack to form a plurality of gap heights, each reflective color of a plurality of reflective colors of the IMOD corresponding with a gap height of the plurality of gap heights.

16. The IMOD of claim 15 , wherein the positioning means includes means for actuating the mirror stack by providing electrical signals to the first metal layer via the hinge area.

17. The IMOD of claim 16 , wherein the hinge area is configured for electrical connectivity with a routing area and wherein the positioning means includes means for providing the electrical signals via the routing area.

18. The IMOD of claim 15 , wherein the hinge area includes at least one non-metal conductor selected from a list of non-metal conductors consisting of carbon, indium tin oxide, tantalum nitride, tantalum oxide, titanium oxide, titanium oxynitride and zirconium oxide.

19. The IMOD of claim 15 , wherein the hinge area includes at least one non-metal conductor selected from a list of non-metal conductors consisting of dielectrics, semiconductors and carbon.

20. The IMOD of claim 15 , wherein the plurality of reflective colors includes more than two colors.

21. The IMOD of claim 15 , further comprising an electrode, wherein the means for positioning the mirror stack includes means for moving the mirror stack away from the absorber stack by applying a voltage between the electrode and the mirror stack.

22. A method of forming an interferometric modulator (IMOD), the method comprising:
forming an absorber stack on a substrate, the absorber stack including an absorber layer;
forming a sacrificial layer on the absorber stack;
forming an anchor area including a plurality of anchors on portions of the absorber stack;
forming a mirror stack including a first metal layer on a mirror stack area of the sacrificial layer, the mirror stack area being within the anchor area;
forming a hinge area on the anchor area to attach and physically connect the mirror stack and the anchor area, wherein forming the hinge area involves forming at least one layer that includes a non-metal conductor configured for electrical connectivity with the first metal layer and wherein forming the hinge area involves forming no metal layer; and
releasing the sacrificial layer to form a gap between the absorber stack and the mirror stack.

23. The method of claim 22 , further comprising configuring the absorber stack and the mirror stack to be configured for being positioned in a plurality of positions relative to one another, to form a plurality of gap heights, each reflective color of a pl

Assignees

• Snaptrack Inc
• Qualcomm Inc

Inventors

• Chang Tallis Young
• Pan Yaoling
• Wen Bing
• Chan Edward Keat Leem

Classifications

• G02F1/21 Primary

  by interference · CPC title

• G02B26/001

  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 title