Flexible video display apparatus and method

• US 7,274,413 B1
• Filed: 12/06/2002
• Issued: 09/25/2007
• Est. Priority Date: 12/06/2002
• Status: Expired due to Fees

• Current Assignee: The Government Of The United States As Represented By The Secretary Of The Navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Russell, Stephen D., Sullivan, Patrick M.
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): Kim; Richard H
• Application Number:
  US10/313,552
• Time in Patent Office: 1,754 Days
• Field of Search: 349/151, 349/43, 349/44, 349/45
• US Class Current: 349/43
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: H01L 27/1266 the substrate on which the devices are formed not being the final device substrate, e.g. using a temporary substrate

Abstract

A flexible video display apparatus and a method for making the same. The flexible video display comprises a silicon layer containing at least a portion of the control and display circuitry, a display layer, and a flexible layer. Other layers, such as an insulating layer for dielectric isolation of the semiconducting devices, may be added. To make the flexible video display, display and control circuitry are formed in a silicon-on-insulator wafer. A polymer layer is then formed on the wafer and electrically conductive portions are formed to interconnect the polymer portions to the control electronics, thereby forming the display. Next, a flexible layer is formed on the display layer and patterned if desired. A handle wafer is then bonded to the topside of the wafer so that the backside can be partially removed by mechanical, chemical, or chemical-mechanical means. Finally, the handle wafer is removed leaving the flexible display.

Claims

1. A flexible video display comprising:

an insulating layer;

a single-crystal silicon layer on said insulating layer;

control and display circuits disposed within said single-crystal silicon layer;

a display layer operably coupled to said control and display circuits disposed within said single-crystal silicon layer; and

a flexible polyimide layer on said display layer.

2. The flexible display of claim 1 wherein said single-crystal silicon layer has a thickness between about 10 nm to about 4500 nm.

3. The flexible display of claim 1 wherein said display layer includes light-modulating materials selected from the group consisting of nematic liquid crystals, twisted-nematic liquid crystals, ferroelectric liquid crystals, electro-optic materials, and microelectromechanical systems.

4. A method for fabricating a flexible video display comprising the steps of:

fabricating display and control circuits in a single-crystal silicon layer of a silicon-on-insulator substrate;

forming a display layer on said display and control circuits in said single-crystal silicon layer of said silicon-on-insulator substrate;

operably coupling said display layer to said display and control circuits fabricated in said single-crystal silicon layer;

forming a flexible polyimide layer on said display layer;

bonding a handle wafer to said silicon-on-insulator substrate;

thinning said silicon-on-insulator substrate; and

removing said handle wafer to form a flexible display.

5. The method of claim 4 wherein said single-crystal silicon layer has a thickness between about 10 nm to about 4500 nm.

6. The method of claim 4 wherein said step of forming a display layer comprises the step of forming light-modulating devices selected from the group consisting of nematic liquid crystals, twisted-nematic liquid crystals, ferroelectric liquid crystals, electro-optic materials, and microelectromechanical systems.

7. The method of claim 4 wherein said step of forming a display layer comprises the step of forming light-emitting displays.

8. The method of claim 4 wherein said step of forming a display layer comprises the step of forming light-emitting devices consisting of organic polymers.

9. A flexible video display comprising:

an insulating layer;

a single-crystal silicon layer on said insulating layer;

control and display circuits disposed within said single-crystal silicon layer;

a light-emitting display layer operably coupled to said control and display circuits disposed within said single-crystal silicon layer; and

a flexible polyimide layer on said light-emitting display layer.

10. The flexible display of claim 9 wherein said single-crystal silicon layer has a thickness between about 10 nm to about 4500 nm.

11. The flexible display of claim 9 wherein said light-emitting display layer comprises organic polymers.