Integrating active matrix inorganic light emitting diodes for display devices

Patent metadata

Field	Value
Publication number	US-9293476-B2
Application number	US-201414518023-A
Country	US
Kind code	B2
Filing date	Oct 20, 2014
Priority date	Nov 23, 2011
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A method of forming an active matrix, light emitting diode (LED) array includes removing, from a base substrate, a layer of inorganic LED material originally grown thereupon; and bonding the removed layer of inorganic LED material to an active matrix, thin film transistor (TFT) backplane array.

First claim

The invention claimed is:

1. An active matrix, light emitting diode (LED) array, comprising:
a first subpixel unit having layer of a first inorganic LED material bonded to an active matrix, thin film transistor (TFT) backplane array; and
a second subpixel unit having a layer of a second inorganic LED material bonded to the active matrix, TFT backplane array; the first inorganic LED material is different from the second inorganic LED material, the first subpixel unit having a different light emission characteristic than the second subpixel unit.

2. The array of claim 1 , further comprising a plurality of color filters formed on at least one of a top and bottom surface of the active matrix TFT backplane array.

3. The array of claim 1 , wherein the inorganic LED material comprises gallium nitride (GaN).

4. The array of claim 1 , further comprising a bottom contact electrode disposed between the backplane array and the inorganic LED material.

5. The array of claim 4 , wherein the bottom contact electrode is one or more of: a transparent conductive oxide (TCO), a metal, and a TCO/metal bilayer.

6. The array of claim 5 , further comprising a top contact electrode formed on a top surface of the inorganic LED material.

7. The array of claim 6 , wherein the top contact electrode is one or more of: a transparent conductive oxide (TCO), a metal, and a TCO/metal bilayer.

8. The array of claim 1 , wherein the layer of inorganic LED material is attached to a flexible handle layer, the flexible handle layer being configured to facilitate a spalling process within the inorganic LED material that exfoliates the inorganic LED material from a base substrate by application of a mechanical force on the flexible handle layer.

9. The array of claim 8 , wherein the flexible handle layer comprises a polyimide material.

10. The array of claim 8 , further comprising one or more stress layers formed between the inorganic LED material and the flexible handle layer.

11. The array of claim 10 , further comprising an adhesion layer that forms an interface between the inorganic LED material and the one or more stress layers.

12. The array of claim 11 , wherein the one or more stress layers comprise metal.

13. The array of claim 12 , wherein a thickness of the one or more stress layers is selected so as exfoliate the inorganic LED material from the base substrate at a desired location with respect to thickness of the exfoliated inorganic LED material.

Assignees

• IBM
• Globalfoundries Inc

Inventors

• Bedell Stephen W
• Hekmatshoartabari Bahman
• Sadana Devendra K
• Shahidi Ghavam G
• Shahrjerdi Davood

Classifications

• H10D86/411

  characterised by materials, geometry or structure of the substrates · CPC title

• H10H20/833

  Transparent materials · CPC title

• H10H20/018

  Bonding of wafers · CPC title

• H10H29/142 Primary

  Two-dimensional arrangements, e.g. asymmetric LED layout · CPC title

• H10D86/60 Primary

  wherein the TFTs are in active matrices · CPC title